diff --git a/SabreTools.DatFiles/DatFile.ToMetadata.cs b/SabreTools.DatFiles/DatFile.ToMetadata.cs
index 65db1e2c..40976da4 100644
--- a/SabreTools.DatFiles/DatFile.ToMetadata.cs
+++ b/SabreTools.DatFiles/DatFile.ToMetadata.cs
@@ -45,6 +45,14 @@ namespace SabreTools.DatFiles
             // Create an internal header
             var header = Header.GetInternalClone();
 
+            // Remove fields with default values
+            if (header.Read<Core.MergingFlag>(Models.Metadata.Header.ForceMergingKey) == Core.MergingFlag.None)
+                header.Remove(Models.Metadata.Header.ForceMergingKey);
+            if (header.Read<Core.NodumpFlag>(Models.Metadata.Header.ForceNodumpKey) == Core.NodumpFlag.None)
+                header.Remove(Models.Metadata.Header.ForceNodumpKey);
+            if (header.Read<Core.PackingFlag>(Models.Metadata.Header.ForcePackingKey) == Core.PackingFlag.None)
+                header.Remove(Models.Metadata.Header.ForcePackingKey);
+
             // Convert subheader values
             if (Header.CanOpenSpecified)
                 header[Models.Metadata.Header.CanOpenKey] = Header.GetFieldValue<Models.OfflineList.CanOpen[]?>(Models.Metadata.Header.CanOpenKey);
diff --git a/SabreTools.DatFiles/DatFile.cs b/SabreTools.DatFiles/DatFile.cs
index 857e06ea..1047978c 100644
--- a/SabreTools.DatFiles/DatFile.cs
+++ b/SabreTools.DatFiles/DatFile.cs
@@ -246,19 +246,21 @@ namespace SabreTools.DatFiles
             }
             else if (item is Rom rom)
             {
+                long? size = NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey));
+
                 // If we have the case where there is SHA-1 and nothing else, we don't fill in any other part of the data
-                if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null && !rom.HasHashes())
+                if (size == null && !rom.HasHashes())
                 {
                     // No-op, just catch it so it doesn't go further
                     logger.Verbose($"{Header.GetFieldValue<string?>(DatHeader.FileNameKey)}: Entry with only SHA-1 found - '{rom.GetName()}'");
                 }
 
                 // If we have a rom and it's missing size AND the hashes match a 0-byte file, fill in the rest of the info
-                else if ((rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == 0 || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null)
+                else if ((size == 0 || size == null)
                     && (string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)) || rom.HasZeroHash()))
                 {
                     // TODO: All instances of Hash.DeepHashes should be made into 0x0 eventually
-                    rom.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, Constants.SizeZero);
+                    rom.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, Constants.SizeZero.ToString());
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, Constants.CRCZero);
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.MD5Key, Constants.MD5Zero);
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, Constants.SHA1Zero);
@@ -269,7 +271,7 @@ namespace SabreTools.DatFiles
                 }
 
                 // If the file has no size and it's not the above case, skip and log
-                else if (rom.GetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey) != ItemStatus.Nodump && (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == 0 || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null))
+                else if (rom.GetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey) != ItemStatus.Nodump && (size == 0 || size == null))
                 {
                     logger.Verbose($"{Header.GetFieldValue<string?>(DatHeader.FileNameKey)}: Incomplete entry for '{rom.GetName()}' will be output as nodump");
                     rom.SetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey, ItemStatus.Nodump);
@@ -277,7 +279,7 @@ namespace SabreTools.DatFiles
 
                 // If the file has a size but aboslutely no hashes, skip and log
                 else if (rom.GetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey) != ItemStatus.Nodump
-                    && rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) != null && rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) > 0
+                    && size != null && size > 0
                     && !rom.HasHashes())
                 {
                     logger.Verbose($"{Header.GetFieldValue<string?>(DatHeader.FileNameKey)}: Incomplete entry for '{rom.GetName()}' will be output as nodump");
@@ -406,7 +408,7 @@ namespace SabreTools.DatFiles
                 sha256 = rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA256Key) ?? string.Empty;
                 sha384 = rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA384Key) ?? string.Empty;
                 sha512 = rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA512Key) ?? string.Empty;
-                size = rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString() ?? string.Empty;
+                size = rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey) ?? string.Empty;
                 spamsum = rom.GetFieldValue<string?>(Models.Metadata.Rom.SpamSumKey) ?? string.Empty;
             }
 
@@ -540,7 +542,7 @@ namespace SabreTools.DatFiles
                 logger.Verbose($"Empty folder found: {datItem.GetFieldValue<Machine>(DatItem.MachineKey)!.GetFieldValue<string?>(Models.Metadata.Machine.NameKey)}");
 
                 rom.SetName(rom.GetName() == "null" ? "-" : rom.GetName());
-                rom.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, Constants.SizeZero);
+                rom.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, Constants.SizeZero.ToString());
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey) == "null" ? Constants.CRCZero : null);
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.MD5Key, rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key) == "null" ? Constants.MD5Zero : null);
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key) == "null" ? Constants.SHA1Zero : null);
@@ -624,7 +626,8 @@ namespace SabreTools.DatFiles
             if (ignoreBlanks && datItem is Rom rom)
             {
                 // If we have a 0-size or blank rom, then we ignore
-                if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == 0 || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null)
+                long? size = NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey));
+                if (size == 0 || size == null)
                 {
                     string itemString = JsonConvert.SerializeObject(datItem, Formatting.None);
                     logger?.Verbose($"Item '{itemString}' was skipped because it had an invalid size");
diff --git a/SabreTools.DatFiles/Formats/ClrMamePro.Writer.cs b/SabreTools.DatFiles/Formats/ClrMamePro.Writer.cs
index 76387a05..23e05890 100644
--- a/SabreTools.DatFiles/Formats/ClrMamePro.Writer.cs
+++ b/SabreTools.DatFiles/Formats/ClrMamePro.Writer.cs
@@ -57,7 +57,7 @@ namespace SabreTools.DatFiles.Formats
                 case Rom rom:
                     if (string.IsNullOrEmpty(rom.GetName()))
                         missingFields.Add(Models.Metadata.Rom.NameKey);
-                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) < 0)
+                    if (rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey) == null || NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < 0)
                         missingFields.Add(Models.Metadata.Rom.SizeKey);
                     if (string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey))
                         && string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key))
@@ -140,7 +140,11 @@ namespace SabreTools.DatFiles.Formats
             {
                 logger.User($"Writing to '{outfile}'...");
 
-                var metadataFile = CreateMetadataFile(ignoreblanks);
+                //var metadataFile = CreateMetadataFile(ignoreblanks);
+
+                // Serialize the input file
+                var metadata = ConvertMetadata(ignoreblanks);
+                var metadataFile = new Serialization.CrossModel.ClrMamePro().Deserialize(metadata);
                 if (!(new Serialization.Files.ClrMamePro().Serialize(metadataFile, outfile, Quotes)))
                 {
                     logger.Warning($"File '{outfile}' could not be written! See the log for more details.");
@@ -370,7 +374,7 @@ namespace SabreTools.DatFiles.Formats
             var rom = new Models.ClrMamePro.Rom
             {
                 Name = item.GetName(),
-                Size = item.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                Size = item.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                 CRC = item.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
                 MD5 = item.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key),
                 SHA1 = item.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key),
diff --git a/SabreTools.DatFiles/Formats/DosCenter.Writer.cs b/SabreTools.DatFiles/Formats/DosCenter.Writer.cs
index 695b4b37..8de2be84 100644
--- a/SabreTools.DatFiles/Formats/DosCenter.Writer.cs
+++ b/SabreTools.DatFiles/Formats/DosCenter.Writer.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using SabreTools.Core;
+using SabreTools.Core.Tools;
 using SabreTools.DatItems;
 using SabreTools.DatItems.Formats;
 
@@ -33,7 +34,7 @@ namespace SabreTools.DatFiles.Formats
             switch (datItem)
             {
                 case Rom rom:
-                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null)
+                    if (rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey) == null || NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < 0)
                         missingFields.Add(Models.Metadata.Rom.SizeKey);
                     // if (string.IsNullOrEmpty(rom.Date))
                     //     missingFields.Add(Models.Metadata.Rom.DateKey);
@@ -179,7 +180,7 @@ namespace SabreTools.DatFiles.Formats
             var rom = new Models.DosCenter.File
             {
                 Name = item.GetName(),
-                Size = item.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                Size = item.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                 CRC = item.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
                 Date = item.GetFieldValue<string?>(Models.Metadata.Rom.DateKey),
             };
diff --git a/SabreTools.DatFiles/Formats/EverdriveSMDB.Writer.cs b/SabreTools.DatFiles/Formats/EverdriveSMDB.Writer.cs
index af1c879e..9697a3d1 100644
--- a/SabreTools.DatFiles/Formats/EverdriveSMDB.Writer.cs
+++ b/SabreTools.DatFiles/Formats/EverdriveSMDB.Writer.cs
@@ -143,7 +143,7 @@ namespace SabreTools.DatFiles.Formats
                 SHA1 = rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key),
                 MD5 = rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key),
                 CRC32 = rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
-                Size = rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                Size = rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
             };
             return row;
         }
diff --git a/SabreTools.DatFiles/Formats/Listrom.Reader.cs b/SabreTools.DatFiles/Formats/Listrom.Reader.cs
index 3f782fa7..3258a491 100644
--- a/SabreTools.DatFiles/Formats/Listrom.Reader.cs
+++ b/SabreTools.DatFiles/Formats/Listrom.Reader.cs
@@ -134,7 +134,7 @@ namespace SabreTools.DatFiles.Formats
                 rom.SetName(row.Name);
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, row.CRC);
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, row.SHA1);
-                rom.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, NumberHelper.ConvertToInt64(row.Size));
+                rom.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, NumberHelper.ConvertToInt64(row.Size).ToString());
                 rom.SetFieldValue<Source?>(DatItem.SourceKey, new Source { Index = indexId, Name = filename });
                 rom.SetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey, ItemStatus.None);
 
@@ -190,7 +190,7 @@ namespace SabreTools.DatFiles.Formats
                 rom.SetName(row.Name);
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, row.CRC);
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, row.SHA1);
-                rom.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, NumberHelper.ConvertToInt64(row.Size));
+                rom.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, NumberHelper.ConvertToInt64(row.Size).ToString());
                 rom.SetFieldValue<Source?>(DatItem.SourceKey, new Source { Index = indexId, Name = filename });
                 rom.SetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey, ItemStatus.BadDump);
 
@@ -207,7 +207,7 @@ namespace SabreTools.DatFiles.Formats
                 rom.SetName(row.Name);
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, null);
                 rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, null);
-                rom.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, NumberHelper.ConvertToInt64(row.Size));
+                rom.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, NumberHelper.ConvertToInt64(row.Size).ToString());
                 rom.SetFieldValue<Source?>(DatItem.SourceKey, new Source { Index = indexId, Name = filename });
                 rom.SetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey, ItemStatus.Nodump);
 
diff --git a/SabreTools.DatFiles/Formats/Listrom.Writer.cs b/SabreTools.DatFiles/Formats/Listrom.Writer.cs
index 12a3d7fb..87bcd5f3 100644
--- a/SabreTools.DatFiles/Formats/Listrom.Writer.cs
+++ b/SabreTools.DatFiles/Formats/Listrom.Writer.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using SabreTools.Core;
+using SabreTools.Core.Tools;
 using SabreTools.DatItems;
 using SabreTools.DatItems.Formats;
 
@@ -42,7 +43,7 @@ namespace SabreTools.DatFiles.Formats
                     break;
 
                 case Rom rom:
-                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) < 0)
+                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < 0)
                         missingFields.Add(Models.Metadata.Rom.SizeKey);
                     if (string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)))
                         missingFields.Add(Models.Metadata.Rom.CRCKey);
@@ -214,7 +215,7 @@ namespace SabreTools.DatFiles.Formats
                 return new Models.Listrom.Row
                 {
                     Name = rom.GetName(),
-                    Size = rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                    Size = rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                     NoGoodDumpKnown = true,
                 };
             }
@@ -223,7 +224,7 @@ namespace SabreTools.DatFiles.Formats
                 return new Models.Listrom.Row
                 {
                     Name = rom.GetName(),
-                    Size = rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                    Size = rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                     Bad = true,
                     CRC = rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
                     SHA1 = rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key),
@@ -234,7 +235,7 @@ namespace SabreTools.DatFiles.Formats
                 return new Models.Listrom.Row
                 {
                     Name = rom.GetName(),
-                    Size = rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                    Size = rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                     CRC = rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
                     SHA1 = rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key),
                 };
diff --git a/SabreTools.DatFiles/Formats/Listxml.Writer.cs b/SabreTools.DatFiles/Formats/Listxml.Writer.cs
index 101f703f..b31dc15d 100644
--- a/SabreTools.DatFiles/Formats/Listxml.Writer.cs
+++ b/SabreTools.DatFiles/Formats/Listxml.Writer.cs
@@ -57,7 +57,7 @@ namespace SabreTools.DatFiles.Formats
                 case Rom rom:
                     if (string.IsNullOrEmpty(rom.GetName()))
                         missingFields.Add(Models.Metadata.Rom.NameKey);
-                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) < 0)
+                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < 0)
                         missingFields.Add(Models.Metadata.Rom.SizeKey);
                     if (string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey))
                         && string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key)))
@@ -420,7 +420,7 @@ namespace SabreTools.DatFiles.Formats
             {
                 Name = item.GetName(),
                 Bios = item.GetFieldValue<string?>(Models.Metadata.Rom.BiosKey),
-                Size = item.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                Size = item.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                 CRC = item.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
                 SHA1 = item.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key),
                 Merge = item.GetFieldValue<string?>(Models.Metadata.Rom.MergeKey),
diff --git a/SabreTools.DatFiles/Formats/Logiqx.Writer.cs b/SabreTools.DatFiles/Formats/Logiqx.Writer.cs
index e50dc189..e68ef7db 100644
--- a/SabreTools.DatFiles/Formats/Logiqx.Writer.cs
+++ b/SabreTools.DatFiles/Formats/Logiqx.Writer.cs
@@ -51,7 +51,7 @@ namespace SabreTools.DatFiles.Formats
                 case Rom rom:
                     if (string.IsNullOrEmpty(rom.GetName()))
                         missingFields.Add(Models.Metadata.Rom.NameKey);
-                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) < 0)
+                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < 0)
                         missingFields.Add(Models.Metadata.Rom.SizeKey);
                     if (string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey))
                         && string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key))
@@ -508,7 +508,7 @@ namespace SabreTools.DatFiles.Formats
             var rom = new Models.Logiqx.Rom
             {
                 Name = item.GetName(),
-                Size = item.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                Size = item.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                 CRC = item.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
                 MD5 = item.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key),
                 SHA1 = item.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key),
diff --git a/SabreTools.DatFiles/Formats/OfflineList.Writer.cs b/SabreTools.DatFiles/Formats/OfflineList.Writer.cs
index 9ba4988f..8ddbd4ed 100644
--- a/SabreTools.DatFiles/Formats/OfflineList.Writer.cs
+++ b/SabreTools.DatFiles/Formats/OfflineList.Writer.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using SabreTools.Core;
+using SabreTools.Core.Tools;
 using SabreTools.DatItems;
 using SabreTools.DatItems.Formats;
 
@@ -33,7 +34,7 @@ namespace SabreTools.DatFiles.Formats
             switch (datItem)
             {
                 case Rom rom:
-                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) < 0)
+                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < 0)
                         missingFields.Add(Models.Metadata.Rom.SizeKey);
                     if (string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)))
                         missingFields.Add(Models.Metadata.Rom.CRCKey);
diff --git a/SabreTools.DatFiles/Formats/RomCenter.Writer.cs b/SabreTools.DatFiles/Formats/RomCenter.Writer.cs
index 6b0d57a7..7f7becb5 100644
--- a/SabreTools.DatFiles/Formats/RomCenter.Writer.cs
+++ b/SabreTools.DatFiles/Formats/RomCenter.Writer.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using SabreTools.Core;
+using SabreTools.Core.Tools;
 using SabreTools.DatItems;
 using SabreTools.DatItems.Formats;
 
@@ -35,7 +36,7 @@ namespace SabreTools.DatFiles.Formats
                 case Rom rom:
                     if (string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)))
                         missingFields.Add(Models.Metadata.Rom.CRCKey);
-                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null)
+                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < 0)
                         missingFields.Add(Models.Metadata.Rom.SizeKey);
                     break;
             }
@@ -189,7 +190,7 @@ namespace SabreTools.DatFiles.Formats
                 GameDescription = item.GetFieldValue<Machine>(DatItem.MachineKey)!.GetFieldValue<string?>(Models.Metadata.Machine.DescriptionKey),
                 RomName = item.GetName(),
                 RomCRC = item.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
-                RomSize = item.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                RomSize = item.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                 RomOf = item.GetFieldValue<Machine>(DatItem.MachineKey)!.GetFieldValue<string?>(Models.Metadata.Machine.RomOfKey),
                 MergeName = item.GetFieldValue<string?>(Models.Metadata.Rom.MergeKey),
             };
diff --git a/SabreTools.DatFiles/Formats/SeparatedValue.Writer.cs b/SabreTools.DatFiles/Formats/SeparatedValue.Writer.cs
index 3a1313d3..71065be7 100644
--- a/SabreTools.DatFiles/Formats/SeparatedValue.Writer.cs
+++ b/SabreTools.DatFiles/Formats/SeparatedValue.Writer.cs
@@ -44,7 +44,7 @@ namespace SabreTools.DatFiles.Formats
                     break;
 
                 case Rom rom:
-                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) < 0)
+                    if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null || NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < 0)
                         missingFields.Add(Models.Metadata.Rom.SizeKey);
                     if (string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey))
                         && string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key))
@@ -223,7 +223,7 @@ namespace SabreTools.DatFiles.Formats
                 Type = rom.GetFieldValue<ItemType>(Models.Metadata.DatItem.TypeKey).AsStringValue<ItemType>(),
                 RomName = rom.GetName(),
                 DiskName = string.Empty,
-                Size = rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                Size = rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                 CRC = rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
                 MD5 = rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key),
                 SHA1 = rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key),
diff --git a/SabreTools.DatFiles/Formats/SoftwareList.Writer.cs b/SabreTools.DatFiles/Formats/SoftwareList.Writer.cs
index 26ba313e..7f74b018 100644
--- a/SabreTools.DatFiles/Formats/SoftwareList.Writer.cs
+++ b/SabreTools.DatFiles/Formats/SoftwareList.Writer.cs
@@ -395,7 +395,7 @@ namespace SabreTools.DatFiles.Formats
             var rom = new Models.SoftwareList.Rom
             {
                 Name = item.GetName(),
-                Size = item.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey)?.ToString(),
+                Size = item.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey),
                 Length = null,
                 CRC = item.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey),
                 SHA1 = item.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key),
diff --git a/SabreTools.DatFiles/ItemDictionary.cs b/SabreTools.DatFiles/ItemDictionary.cs
index cb3f2fc0..3ee78a9f 100644
--- a/SabreTools.DatFiles/ItemDictionary.cs
+++ b/SabreTools.DatFiles/ItemDictionary.cs
@@ -11,6 +11,7 @@ using System.Threading.Tasks;
 using System.Xml.Serialization;
 using Newtonsoft.Json;
 using SabreTools.Core;
+using SabreTools.Core.Tools;
 using SabreTools.DatItems;
 using SabreTools.DatItems.Formats;
 using SabreTools.Hashing;
@@ -249,7 +250,7 @@ namespace SabreTools.DatFiles
                     case Rom rom:
                         if (rom.GetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey) != ItemStatus.Nodump)
                         {
-                            TotalSize += rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) ?? 0;
+                            TotalSize += NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) ?? 0;
                             AddHashCount(HashType.CRC32, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)) ? 0 : 1);
                             AddHashCount(HashType.MD5, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key)) ? 0 : 1);
                             AddHashCount(HashType.SHA1, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key)) ? 0 : 1);
@@ -530,7 +531,7 @@ namespace SabreTools.DatFiles
                     case Rom rom:
                         if (rom.GetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey) != ItemStatus.Nodump)
                         {
-                            TotalSize -= rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) ?? 0;
+                            TotalSize -= NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) ?? 0;
                             RemoveHashCount(HashType.CRC32, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)) ? 0 : 1);
                             RemoveHashCount(HashType.MD5, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key)) ? 0 : 1);
                             RemoveHashCount(HashType.SHA1, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key)) ? 0 : 1);
diff --git a/SabreTools.DatFiles/ItemDictionaryDB.cs b/SabreTools.DatFiles/ItemDictionaryDB.cs
index f4e0e7e3..5ef7ca51 100644
--- a/SabreTools.DatFiles/ItemDictionaryDB.cs
+++ b/SabreTools.DatFiles/ItemDictionaryDB.cs
@@ -10,6 +10,7 @@ using System.Xml.Serialization;
 using Microsoft.Data.Sqlite;
 using Newtonsoft.Json;
 using SabreTools.Core;
+using SabreTools.Core.Tools;
 using SabreTools.DatItems;
 using SabreTools.DatItems.Formats;
 using SabreTools.Hashing;
@@ -366,7 +367,7 @@ namespace SabreTools.DatFiles
                     case Rom rom:
                         if (rom.GetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey) != ItemStatus.Nodump)
                         {
-                            TotalSize += rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) ?? 0;
+                            TotalSize += NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) ?? 0;
                             AddHashCount(HashType.CRC32, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)) ? 0 : 1);
                             AddHashCount(HashType.MD5, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key)) ? 0 : 1);
                             AddHashCount(HashType.SHA1, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key)) ? 0 : 1);
@@ -674,7 +675,7 @@ namespace SabreTools.DatFiles
                     case Rom rom:
                         if (rom.GetFieldValue<ItemStatus>(Models.Metadata.Rom.StatusKey) != ItemStatus.Nodump)
                         {
-                            TotalSize -= rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) ?? 0;
+                            TotalSize -= NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) ?? 0;
                             RemoveHashCount(HashType.CRC32, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)) ? 0 : 1);
                             RemoveHashCount(HashType.MD5, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.MD5Key)) ? 0 : 1);
                             RemoveHashCount(HashType.SHA1, string.IsNullOrEmpty(rom.GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key)) ? 0 : 1);
diff --git a/SabreTools.DatItems/Formats/Rom.cs b/SabreTools.DatItems/Formats/Rom.cs
index ca24d369..6a3311b8 100644
--- a/SabreTools.DatItems/Formats/Rom.cs
+++ b/SabreTools.DatItems/Formats/Rom.cs
@@ -100,7 +100,7 @@ namespace SabreTools.DatItems.Formats
             SetFieldValue<string?>(Models.Metadata.Rom.SHA256Key, TextHelper.ByteArrayToString(baseFile.SHA256));
             SetFieldValue<string?>(Models.Metadata.Rom.SHA384Key, TextHelper.ByteArrayToString(baseFile.SHA384));
             SetFieldValue<string?>(Models.Metadata.Rom.SHA512Key, TextHelper.ByteArrayToString(baseFile.SHA512));
-            SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, baseFile.Size);
+            SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, baseFile.Size.ToString());
             SetFieldValue<string?>(Models.Metadata.Rom.SpamSumKey, System.Text.Encoding.UTF8.GetString(baseFile.SpamSum ?? []));
 
             SetFieldValue<DupeType>(DatItem.DupeTypeKey, 0x00);
@@ -127,7 +127,7 @@ namespace SabreTools.DatItems.Formats
                 Filename = GetName(),
                 Parent = GetFieldValue<Machine>(DatItem.MachineKey)!.GetFieldValue<string?>(Models.Metadata.Machine.NameKey),
                 Date = GetFieldValue<string?>(Models.Metadata.Rom.DateKey),
-                Size = GetFieldValue<long?>(Models.Metadata.Rom.SizeKey),
+                Size = NumberHelper.ConvertToInt64(GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)),
                 CRC = TextHelper.StringToByteArray(GetFieldValue<string?>(Models.Metadata.Rom.CRCKey)),
                 MD5 = TextHelper.StringToByteArray(GetFieldValue<string?>(Models.Metadata.Rom.MD5Key)),
                 SHA1 = TextHelper.StringToByteArray(GetFieldValue<string?>(Models.Metadata.Rom.SHA1Key)),
diff --git a/SabreTools.DatTools/Splitter.cs b/SabreTools.DatTools/Splitter.cs
index bb83d56e..b3d51a1e 100644
--- a/SabreTools.DatTools/Splitter.cs
+++ b/SabreTools.DatTools/Splitter.cs
@@ -7,6 +7,7 @@ using System.Net;
 using System.Threading.Tasks;
 #endif
 using SabreTools.Core;
+using SabreTools.Core.Tools;
 using SabreTools.DatFiles;
 using SabreTools.DatItems;
 using SabreTools.DatItems.Formats;
@@ -412,15 +413,15 @@ namespace SabreTools.DatTools
                         lessThan.Items.Add(key, item);
 
                     // If the file is a Rom and has no size, put it in the "lesser" dat
-                    else if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) == null)
+                    else if (rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey) == null)
                         lessThan.Items.Add(key, item);
 
                     // If the file is a Rom and less than the radix, put it in the "lesser" dat
-                    else if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) < radix)
+                    else if (NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) < radix)
                         lessThan.Items.Add(key, item);
 
                     // If the file is a Rom and greater than or equal to the radix, put it in the "greater" dat
-                    else if (rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) >= radix)
+                    else if (NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) >= radix)
                         greaterThan.Items.Add(key, item);
                 }
 #if NET40_OR_GREATER || NETCOREAPP
@@ -484,8 +485,8 @@ namespace SabreTools.DatTools
                     if (item is Rom rom)
                     {
                         // TODO: Should there be more than just a log if a single item is larger than the chunksize?
-                        machineSize += rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) ?? 0;
-                        if ((rom.GetFieldValue<long?>(Models.Metadata.Rom.SizeKey) ?? 0) > chunkSize)
+                        machineSize += NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) ?? 0;
+                        if ((NumberHelper.ConvertToInt64(rom.GetFieldValue<string?>(Models.Metadata.Rom.SizeKey)) ?? 0) > chunkSize)
                             logger.Error($"{rom.GetName() ?? string.Empty} in {machine} is larger than {chunkSize}");
                     }
                 }
diff --git a/SabreTools.Test/DatFiles/ItemDictionaryTests.cs b/SabreTools.Test/DatFiles/ItemDictionaryTests.cs
index 92d0dcda..dda569ee 100644
--- a/SabreTools.Test/DatFiles/ItemDictionaryTests.cs
+++ b/SabreTools.Test/DatFiles/ItemDictionaryTests.cs
@@ -25,28 +25,28 @@ namespace SabreTools.Test.DatFiles
             rom1.SetName("rom-1");
             rom1.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, "DEADBEEF");
             rom1.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "0000000fbbb37f8488100b1b4697012de631a5e6");
-            rom1.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom1.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine1);
 
             var rom2 = new Rom();
             rom2.SetName("rom-2");
             rom2.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, "DEADBEEF");
             rom2.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "000000e948edcb4f7704b8af85a77a3339ecce44");
-            rom2.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom2.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine1);
 
             var rom3 = new Rom();
             rom3.SetName("rom-3");
             rom3.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, "DEADBEEF");
             rom3.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "00000ea4014ce66679e7e17d56ac510f67e39e26");
-            rom3.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom3.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine2);
 
             var rom4 = new Rom();
             rom4.SetName("rom-4");
             rom4.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, "DEADBEEF");
             rom4.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "00000151d437442e74e5134023fab8bf694a2487");
-            rom4.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom4.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine2);
 
             // Setup the dictionary
@@ -86,7 +86,7 @@ namespace SabreTools.Test.DatFiles
             rom1.SetName("rom-1");
             rom1.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, "DEADBEEF");
             rom1.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "0000000fbbb37f8488100b1b4697012de631a5e6");
-            rom1.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom1.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine1);
 
             var rom2 = new Rom();
@@ -94,7 +94,7 @@ namespace SabreTools.Test.DatFiles
             rom2.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, "DEADBEEF");
             rom2.SetFieldValue<bool?>(DatItem.RemoveKey, true);
             rom2.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "000000e948edcb4f7704b8af85a77a3339ecce44");
-            rom2.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom2.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine1);
 
             // Setup the dictionary
@@ -122,13 +122,13 @@ namespace SabreTools.Test.DatFiles
             var rom1 = new Rom();
             rom1.SetName("rom-1");
             rom1.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "0000000fbbb37f8488100b1b4697012de631a5e6");
-            rom1.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom1.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine1);
 
             var rom2 = new Rom();
             rom2.SetName("rom-2");
             rom2.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "000000e948edcb4f7704b8af85a77a3339ecce44");
-            rom2.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom2.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine1);
 
             // Setup the dictionary
@@ -141,7 +141,7 @@ namespace SabreTools.Test.DatFiles
             var rom = new Rom();
             rom.SetName("rom-1");
             rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "0000000fbbb37f8488100b1b4697012de631a5e6");
-            rom.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, hasDuplicate ? 1024 : 2048);
+            rom.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, hasDuplicate ? "1024" : "2048");
             rom1.CopyMachineInformation(machine1);
 
             var actual = dict.GetDuplicates(rom);
@@ -160,13 +160,13 @@ namespace SabreTools.Test.DatFiles
             var rom1 = new Rom();
             rom1.SetName("rom-1");
             rom1.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "0000000fbbb37f8488100b1b4697012de631a5e6");
-            rom1.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom1.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine1);
 
             var rom2 = new Rom();
             rom2.SetName("rom-2");
             rom2.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "000000e948edcb4f7704b8af85a77a3339ecce44");
-            rom2.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, 1024);
+            rom2.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, "1024");
             rom1.CopyMachineInformation(machine1);
 
             // Setup the dictionary
@@ -179,7 +179,7 @@ namespace SabreTools.Test.DatFiles
             var rom = new Rom();
             rom.SetName("rom-1");
             rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "0000000fbbb37f8488100b1b4697012de631a5e6");
-            rom.SetFieldValue<long?>(Models.Metadata.Rom.SizeKey, expected ? 1024 : 2048);
+            rom.SetFieldValue<string?>(Models.Metadata.Rom.SizeKey, expected ? "1024" : "2048");
             rom1.CopyMachineInformation(machine1);
 
             bool actual = dict.HasDuplicates(rom);