diff --git a/SabreTools.DatFiles.Test/ReplacerTests.cs b/SabreTools.DatFiles.Test/ReplacerTests.cs
index 417c8a6b..f0538b8d 100644
--- a/SabreTools.DatFiles.Test/ReplacerTests.cs
+++ b/SabreTools.DatFiles.Test/ReplacerTests.cs
@@ -1,6 +1,8 @@
 using System.Collections.Generic;
+using SabreTools.Core.Tools;
 using SabreTools.DatItems;
 using SabreTools.DatItems.Formats;
+using SabreTools.Hashing;
 using Xunit;
 
 namespace SabreTools.DatFiles.Test
@@ -27,85 +29,164 @@ namespace SabreTools.DatFiles.Test
             Assert.Equal("foo", machine.GetStringFieldValue(Models.Metadata.Machine.NameKey));
         }
 
-        // TODO: Check more fields for replacement
         [Fact]
         public void ReplaceFields_Disk()
         {
             var datItem = new Disk();
             datItem.SetName("foo");
+            datItem.SetFieldValue<string?>(Models.Metadata.Disk.MD5Key, ZeroHash.MD5Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Disk.SHA1Key, ZeroHash.SHA1Str);
 
             var repDatItem = new Disk();
             repDatItem.SetName("bar");
+            repDatItem.SetFieldValue<string?>(Models.Metadata.Disk.MD5Key, "deadbeef");
+            repDatItem.SetFieldValue<string?>(Models.Metadata.Disk.SHA1Key, "deadbeef");
 
             var fields = new Dictionary<string, List<string>>
             {
-                ["item"] = [Models.Metadata.Disk.NameKey]
+                ["item"] =
+                [
+                    Models.Metadata.Disk.NameKey,
+                    Models.Metadata.Disk.MD5Key,
+                    Models.Metadata.Disk.SHA1Key,
+                ]
             };
 
             Replacer.ReplaceFields(datItem, repDatItem, fields);
 
             Assert.Equal("bar", datItem.GetName());
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Disk.MD5Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Disk.SHA1Key));
         }
 
-        // TODO: Check more fields for replacement
         [Fact]
         public void ReplaceFields_File()
         {
             var datItem = new DatItems.Formats.File();
-            datItem.SetName("foo");
+            datItem.CRC = ZeroHash.CRC32Str;
+            datItem.MD5 = ZeroHash.MD5Str;
+            datItem.SHA1 = ZeroHash.SHA1Str;
+            datItem.SHA256 = ZeroHash.SHA256Str;
 
             var repDatItem = new DatItems.Formats.File();
-            repDatItem.SetName("bar");
+            repDatItem.CRC = TextHelper.NormalizeCRC32("deadbeef");
+            repDatItem.MD5 = TextHelper.NormalizeMD5("deadbeef");
+            repDatItem.SHA1 = TextHelper.NormalizeSHA1("deadbeef");
+            repDatItem.SHA256 = TextHelper.NormalizeSHA256("deadbeef");
 
             var fields = new Dictionary<string, List<string>>
             {
-                ["item"] = [Models.Metadata.Rom.NameKey]
+                ["item"] =
+                [
+                    Models.Metadata.Rom.CRCKey,
+                    Models.Metadata.Rom.MD5Key,
+                    Models.Metadata.Rom.SHA1Key,
+                    Models.Metadata.Rom.SHA256Key,
+                ]
             };
 
             Replacer.ReplaceFields(datItem, repDatItem, fields);
 
-            // TODO: There is no name field for File type
-            //Assert.Equal("bar", datItem.GetName());
+            Assert.Equal(TextHelper.NormalizeCRC32("deadbeef"), datItem.CRC);
+            Assert.Equal(TextHelper.NormalizeMD5("deadbeef"), datItem.MD5);
+            Assert.Equal(TextHelper.NormalizeSHA1("deadbeef"), datItem.SHA1);
+            Assert.Equal(TextHelper.NormalizeSHA256("deadbeef"), datItem.SHA256);
         }
 
-        // TODO: Check more fields for replacement
         [Fact]
         public void ReplaceFields_Media()
         {
             var datItem = new Media();
             datItem.SetName("foo");
+            datItem.SetFieldValue<string?>(Models.Metadata.Media.MD5Key, ZeroHash.MD5Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Media.SHA1Key, ZeroHash.SHA1Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Media.SHA256Key, ZeroHash.SHA256Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Media.SpamSumKey, ZeroHash.SpamSumStr);
 
             var repDatItem = new Media();
             repDatItem.SetName("bar");
+            datItem.SetFieldValue<string?>(Models.Metadata.Media.MD5Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Media.SHA1Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Media.SHA256Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Media.SpamSumKey, "deadbeef");
 
             var fields = new Dictionary<string, List<string>>
             {
-                ["item"] = [Models.Metadata.Media.NameKey]
+                ["item"] =
+                [
+                    Models.Metadata.Media.NameKey,
+                    Models.Metadata.Media.MD5Key,
+                    Models.Metadata.Media.SHA1Key,
+                    Models.Metadata.Media.SHA256Key,
+                    Models.Metadata.Media.SpamSumKey,
+                ]
             };
 
             Replacer.ReplaceFields(datItem, repDatItem, fields);
 
             Assert.Equal("bar", datItem.GetName());
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Media.MD5Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Media.SHA1Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Media.SHA256Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Media.SpamSumKey));
         }
 
-        // TODO: Check more fields for replacement
         [Fact]
         public void ReplaceFields_Rom()
         {
             var datItem = new Rom();
             datItem.SetName("foo");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, ZeroHash.CRC32Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.MD2Key, ZeroHash.GetString(HashType.MD2));
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.MD4Key, ZeroHash.GetString(HashType.MD4));
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.MD5Key, ZeroHash.MD5Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, ZeroHash.SHA1Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SHA256Key, ZeroHash.SHA256Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SHA384Key, ZeroHash.SHA384Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SHA512Key, ZeroHash.SHA512Str);
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SpamSumKey, ZeroHash.SpamSumStr);
 
             var repDatItem = new Rom();
             repDatItem.SetName("bar");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.MD2Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.MD4Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.MD5Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SHA256Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SHA384Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SHA512Key, "deadbeef");
+            datItem.SetFieldValue<string?>(Models.Metadata.Rom.SpamSumKey, "deadbeef");
 
             var fields = new Dictionary<string, List<string>>
             {
-                ["item"] = [Models.Metadata.Rom.NameKey]
+                ["item"] =
+                [
+                    Models.Metadata.Rom.NameKey,
+                    Models.Metadata.Rom.CRCKey,
+                    Models.Metadata.Rom.MD2Key,
+                    Models.Metadata.Rom.MD4Key,
+                    Models.Metadata.Rom.MD5Key,
+                    Models.Metadata.Rom.SHA1Key,
+                    Models.Metadata.Rom.SHA256Key,
+                    Models.Metadata.Rom.SHA384Key,
+                    Models.Metadata.Rom.SHA512Key,
+                    Models.Metadata.Rom.SpamSumKey,
+                ]
             };
 
             Replacer.ReplaceFields(datItem, repDatItem, fields);
 
             Assert.Equal("bar", datItem.GetName());
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.CRCKey));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.MD2Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.MD4Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.MD5Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.SHA1Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.SHA256Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.SHA384Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.SHA512Key));
+            Assert.Equal("deadbeef", datItem.GetStringFieldValue(Models.Metadata.Rom.SpamSumKey));
         }
 
         [Fact]
diff --git a/SabreTools.DatFiles/Replacer.cs b/SabreTools.DatFiles/Replacer.cs
index 399b4d4e..40e7a2dd 100644
--- a/SabreTools.DatFiles/Replacer.cs
+++ b/SabreTools.DatFiles/Replacer.cs
@@ -105,13 +105,13 @@ namespace SabreTools.DatFiles
         {
             if (datItemFields.Contains(Models.Metadata.Disk.MD5Key))
             {
-                if (string.IsNullOrEmpty(disk.GetStringFieldValue(Models.Metadata.Disk.MD5Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Disk.MD5Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Disk.MD5Key)))
                     disk.SetFieldValue<string?>(Models.Metadata.Disk.MD5Key, newItem.GetStringFieldValue(Models.Metadata.Disk.MD5Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Disk.SHA1Key))
             {
-                if (string.IsNullOrEmpty(disk.GetStringFieldValue(Models.Metadata.Disk.SHA1Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Disk.SHA1Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Disk.SHA1Key)))
                     disk.SetFieldValue<string?>(Models.Metadata.Disk.SHA1Key, newItem.GetStringFieldValue(Models.Metadata.Disk.SHA1Key));
             }
         }
@@ -126,25 +126,25 @@ namespace SabreTools.DatFiles
         {
             if (datItemFields.Contains(Models.Metadata.Rom.CRCKey))
             {
-                if (string.IsNullOrEmpty(file.CRC) && !string.IsNullOrEmpty(newItem.CRC))
+                if (!string.IsNullOrEmpty(newItem.CRC))
                     file.CRC = newItem.CRC;
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.MD5Key))
             {
-                if (string.IsNullOrEmpty(file.MD5) && !string.IsNullOrEmpty(newItem.MD5))
+                if (!string.IsNullOrEmpty(newItem.MD5))
                     file.MD5 = newItem.MD5;
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.SHA1Key))
             {
-                if (string.IsNullOrEmpty(file.SHA1) && !string.IsNullOrEmpty(newItem.SHA1))
+                if (!string.IsNullOrEmpty(newItem.SHA1))
                     file.SHA1 = newItem.SHA1;
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.SHA256Key))
             {
-                if (string.IsNullOrEmpty(file.SHA256) && !string.IsNullOrEmpty(newItem.SHA256))
+                if (!string.IsNullOrEmpty(newItem.SHA256))
                     file.SHA256 = newItem.SHA256;
             }
         }
@@ -159,25 +159,25 @@ namespace SabreTools.DatFiles
         {
             if (datItemFields.Contains(Models.Metadata.Media.MD5Key))
             {
-                if (string.IsNullOrEmpty(media.GetStringFieldValue(Models.Metadata.Media.MD5Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Media.MD5Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Media.MD5Key)))
                     media.SetFieldValue<string?>(Models.Metadata.Media.MD5Key, newItem.GetStringFieldValue(Models.Metadata.Media.MD5Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Media.SHA1Key))
             {
-                if (string.IsNullOrEmpty(media.GetStringFieldValue(Models.Metadata.Media.SHA1Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Media.SHA1Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Media.SHA1Key)))
                     media.SetFieldValue<string?>(Models.Metadata.Media.SHA1Key, newItem.GetStringFieldValue(Models.Metadata.Media.SHA1Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Media.SHA256Key))
             {
-                if (string.IsNullOrEmpty(media.GetStringFieldValue(Models.Metadata.Media.SHA256Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Media.SHA256Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Media.SHA256Key)))
                     media.SetFieldValue<string?>(Models.Metadata.Media.SHA256Key, newItem.GetStringFieldValue(Models.Metadata.Media.SHA256Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Media.SpamSumKey))
             {
-                if (string.IsNullOrEmpty(media.GetStringFieldValue(Models.Metadata.Media.SpamSumKey)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Media.SpamSumKey)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Media.SpamSumKey)))
                     media.SetFieldValue<string?>(Models.Metadata.Media.SpamSumKey, newItem.GetStringFieldValue(Models.Metadata.Media.SpamSumKey));
             }
         }
@@ -192,55 +192,55 @@ namespace SabreTools.DatFiles
         {
             if (datItemFields.Contains(Models.Metadata.Rom.CRCKey))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.CRCKey)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.CRCKey)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.CRCKey)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.CRCKey, newItem.GetStringFieldValue(Models.Metadata.Rom.CRCKey));
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.MD2Key))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.MD2Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.MD2Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.MD2Key)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.MD2Key, newItem.GetStringFieldValue(Models.Metadata.Rom.MD2Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.MD4Key))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.MD4Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.MD4Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.MD4Key)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.MD4Key, newItem.GetStringFieldValue(Models.Metadata.Rom.MD4Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.MD5Key))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.MD5Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.MD5Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.MD5Key)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.MD5Key, newItem.GetStringFieldValue(Models.Metadata.Rom.MD5Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.SHA1Key))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.SHA1Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SHA1Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SHA1Key)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA1Key, newItem.GetStringFieldValue(Models.Metadata.Rom.SHA1Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.SHA256Key))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.SHA256Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SHA256Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SHA256Key)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA256Key, newItem.GetStringFieldValue(Models.Metadata.Rom.SHA256Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.SHA384Key))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.SHA384Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SHA384Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SHA384Key)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA384Key, newItem.GetStringFieldValue(Models.Metadata.Rom.SHA384Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.SHA512Key))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.SHA512Key)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SHA512Key)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SHA512Key)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.SHA512Key, newItem.GetStringFieldValue(Models.Metadata.Rom.SHA512Key));
             }
 
             if (datItemFields.Contains(Models.Metadata.Rom.SpamSumKey))
             {
-                if (string.IsNullOrEmpty(rom.GetStringFieldValue(Models.Metadata.Rom.SpamSumKey)) && !string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SpamSumKey)))
+                if (!string.IsNullOrEmpty(newItem.GetStringFieldValue(Models.Metadata.Rom.SpamSumKey)))
                     rom.SetFieldValue<string?>(Models.Metadata.Rom.SpamSumKey, newItem.GetStringFieldValue(Models.Metadata.Rom.SpamSumKey));
             }
         }