diff --git a/PortableExecutable/BaseRelocationTypeOffsetFieldEntry.cs b/PortableExecutable/BaseRelocationTypeOffsetFieldEntry.cs
index 95a940f..eef727e 100644
--- a/PortableExecutable/BaseRelocationTypeOffsetFieldEntry.cs
+++ b/PortableExecutable/BaseRelocationTypeOffsetFieldEntry.cs
@@ -1,12 +1,9 @@
-using System.Runtime.InteropServices;
-
-namespace SabreTools.Models.PortableExecutable
+namespace SabreTools.Models.PortableExecutable
 {
     /// <summary>
     /// Type or Offset field entry is a WORD (2 bytes).
     /// </summary>
     /// <see href="https://learn.microsoft.com/en-us/windows/win32/debug/pe-format"/>
-    [StructLayout(LayoutKind.Sequential)]
     public sealed class BaseRelocationTypeOffsetFieldEntry
     {
         /// <summary>
diff --git a/PortableExecutable/HintNameTableEntry.cs b/PortableExecutable/HintNameTableEntry.cs
index 2ced00c..250afd7 100644
--- a/PortableExecutable/HintNameTableEntry.cs
+++ b/PortableExecutable/HintNameTableEntry.cs
@@ -1,9 +1,12 @@
-namespace SabreTools.Models.PortableExecutable
+using System.Runtime.InteropServices;
+
+namespace SabreTools.Models.PortableExecutable
 {
     /// <summary>
     /// One hint/name table suffices for the entire import section.
     /// </summary>
     /// <see href="https://learn.microsoft.com/en-us/windows/win32/debug/pe-format"/>
+    [StructLayout(LayoutKind.Sequential)]
     public sealed class HintNameTableEntry
     {
         /// <summary>
@@ -11,13 +14,14 @@
         /// with this value. If it fails, a binary search is performed on the DLL's
         /// export name pointer table.
         /// </summary>
-        public ushort Hint { get; set; }
+        public ushort Hint;
 
         /// <summary>
         /// An ASCII string that contains the name to import. This is the string that
         /// must be matched to the public name in the DLL. This string is case sensitive
         /// and terminated by a null byte.
         /// </summary>
-        public string? Name { get; set; }
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string? Name;
     }
 }
diff --git a/PortableExecutable/MenuItem.cs b/PortableExecutable/MenuItem.cs
index 8920688..847d5a5 100644
--- a/PortableExecutable/MenuItem.cs
+++ b/PortableExecutable/MenuItem.cs
@@ -1,62 +1,9 @@
 namespace SabreTools.Models.PortableExecutable
 {
     /// <summary>
-    /// Contains information about each item in a menu resource that does not open a menu
-    /// or a submenu. The structure definition provided here is for explanation only; it
-    /// is not present in any standard header file.
-    /// 
-    /// Contains information about the menu items in a menu resource that open a menu
-    /// or a submenu. The structure definition provided here is for explanation only;
-    /// it is not present in any standard header file.
+    /// Common base class for menu item types
     /// </summary>
     /// <see href="https://learn.microsoft.com/en-us/windows/win32/menurc/normalmenuitem"/>
     /// <see href="https://learn.microsoft.com/en-us/windows/win32/menurc/popupmenuitem"/>
-    public sealed class MenuItem
-    {
-        #region NORMALMENUITEM
-
-        /// <summary>
-        /// The type of menu item.
-        /// </summary>
-        public MenuFlags NormalResInfo { get; set; }
-
-        /// <summary>
-        /// A null-terminated Unicode string that contains the text for this menu item.
-        /// There is no fixed limit on the size of this string.
-        /// </summary>
-        public string? NormalMenuText { get; set; }
-
-        #endregion
-
-        #region POPUPMENUITEM
-
-        /// <summary>
-        /// Describes the menu item.
-        /// </summary>
-        public MenuFlags PopupItemType { get; set; }
-
-        /// <summary>
-        /// Describes the menu item.
-        /// </summary>
-        public MenuFlags PopupState { get; set; }
-
-        /// <summary>
-        /// A numeric expression that identifies the menu item that is passed in the
-        /// WM_COMMAND message.
-        /// </summary>
-        public uint PopupID { get; set; }
-
-        /// <summary>
-        /// A set of bit flags that specify the type of menu item.
-        /// </summary>
-        public MenuFlags PopupResInfo { get; set; }
-
-        /// <summary>
-        /// A null-terminated Unicode string that contains the text for this menu item.
-        /// There is no fixed limit on the size of this string.
-        /// </summary>
-        public string? PopupMenuText { get; set; }
-
-        #endregion
-    }
+    public abstract class MenuItem { }
 }
diff --git a/PortableExecutable/NB10ProgramDatabase.cs b/PortableExecutable/NB10ProgramDatabase.cs
index 70ac2ea..2d1cdf5 100644
--- a/PortableExecutable/NB10ProgramDatabase.cs
+++ b/PortableExecutable/NB10ProgramDatabase.cs
@@ -35,8 +35,9 @@ namespace SabreTools.Models.PortableExecutable
 
         /// <summary>
         /// Null-terminated name of the PDB file. It can also contain full
-        /// or partial path to the file. 
+        /// or partial path to the file.
         /// </summary>
+        /// <remarks>Is this Unicode?</remarks>
         [MarshalAs(UnmanagedType.LPStr)]
         public string? PdbFileName;
     }
diff --git a/PortableExecutable/NormalMenuItem.cs b/PortableExecutable/NormalMenuItem.cs
new file mode 100644
index 0000000..8176c0e
--- /dev/null
+++ b/PortableExecutable/NormalMenuItem.cs
@@ -0,0 +1,27 @@
+using System.Runtime.InteropServices;
+
+namespace SabreTools.Models.PortableExecutable
+{
+    /// <summary>
+    /// Contains information about each item in a menu resource that does not open a menu
+    /// or a submenu. The structure definition provided here is for explanation only; it
+    /// is not present in any standard header file.
+    /// </summary>
+    /// <see href="https://learn.microsoft.com/en-us/windows/win32/menurc/normalmenuitem"/>
+    [StructLayout(LayoutKind.Sequential)]
+    public sealed class NormalMenuItem : MenuItem
+    {
+        /// <summary>
+        /// The type of menu item.
+        /// </summary>
+        [MarshalAs(UnmanagedType.U2)]
+        public MenuFlags NormalResInfo;
+
+        /// <summary>
+        /// A null-terminated Unicode string that contains the text for this menu item.
+        /// There is no fixed limit on the size of this string.
+        /// </summary>
+        [MarshalAs(UnmanagedType.LPWStr)]
+        public string? NormalMenuText;
+    }
+}
diff --git a/PortableExecutable/PopupMenuItem.cs b/PortableExecutable/PopupMenuItem.cs
new file mode 100644
index 0000000..5b6ab76
--- /dev/null
+++ b/PortableExecutable/PopupMenuItem.cs
@@ -0,0 +1,45 @@
+using System.Runtime.InteropServices;
+
+namespace SabreTools.Models.PortableExecutable
+{
+    /// <summary>
+    /// Contains information about the menu items in a menu resource that open a menu
+    /// or a submenu. The structure definition provided here is for explanation only;
+    /// it is not present in any standard header file.
+    /// </summary>
+    /// <see href="https://learn.microsoft.com/en-us/windows/win32/menurc/popupmenuitem"/>
+    [StructLayout(LayoutKind.Sequential)]
+    public sealed class PopupMenuItem : MenuItem
+    {
+        /// <summary>
+        /// Describes the menu item.
+        /// </summary>
+        [MarshalAs(UnmanagedType.U4)]
+        public MenuFlags PopupItemType;
+
+        /// <summary>
+        /// Describes the menu item.
+        /// </summary>
+        [MarshalAs(UnmanagedType.U4)]
+        public MenuFlags PopupState;
+
+        /// <summary>
+        /// A numeric expression that identifies the menu item that is passed in the
+        /// WM_COMMAND message.
+        /// </summary>
+        public uint PopupID;
+
+        /// <summary>
+        /// A set of bit flags that specify the type of menu item.
+        /// </summary>
+        [MarshalAs(UnmanagedType.U4)]
+        public MenuFlags PopupResInfo;
+
+        /// <summary>
+        /// A null-terminated Unicode string that contains the text for this menu item.
+        /// There is no fixed limit on the size of this string.
+        /// </summary>
+        [MarshalAs(UnmanagedType.LPWStr)]
+        public string? PopupMenuText;
+    }
+}
diff --git a/PortableExecutable/RSDSProgramDatabase.cs b/PortableExecutable/RSDSProgramDatabase.cs
index 3c6a992..d7ef7d8 100644
--- a/PortableExecutable/RSDSProgramDatabase.cs
+++ b/PortableExecutable/RSDSProgramDatabase.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Runtime.InteropServices;
 
 namespace SabreTools.Models.PortableExecutable
 {
@@ -7,28 +8,30 @@ namespace SabreTools.Models.PortableExecutable
     /// or "DS" type which are emitted by Miscrosoft's link.exe from version 7 and above.
     /// </summary>
     /// <see href="http://www.godevtool.com/Other/pdb.htm"/>
+    [StructLayout(LayoutKind.Sequential)]
     public sealed class RSDSProgramDatabase
     {
         /// <summary>
         /// "RSDS" signature
         /// </summary>
-        public uint Signature { get; set; }
+        public uint Signature;
 
         /// <summary>
         /// 16-byte Globally Unique Identifier
         /// </summary>
-        public Guid GUID { get; set; }
+        public Guid GUID;
 
         /// <summary>
         /// Ever-incrementing value, which is initially set to 1 and
         /// incremented every time when a part of the PDB file is updated
         /// without rewriting the whole file. 
         /// </summary>
-        public uint Age { get; set; }
+        public uint Age;
 
         /// <summary>
         /// zero terminated UTF8 path and file name
         /// </summary>
-        public string? PathAndFileName { get; set; }
+        [MarshalAs(UnmanagedType.LPWStr)]
+        public string? PathAndFileName;
     }
 }
diff --git a/PortableExecutable/SecuROMAddD.cs b/PortableExecutable/SecuROMAddD.cs
index 6311cf0..844aa6f 100644
--- a/PortableExecutable/SecuROMAddD.cs
+++ b/PortableExecutable/SecuROMAddD.cs
@@ -1,4 +1,6 @@
-namespace SabreTools.Models.PortableExecutable
+using System.Runtime.InteropServices;
+
+namespace SabreTools.Models.PortableExecutable
 {
     /// <summary>
     /// Overlay data associated with SecuROM executables
@@ -15,7 +17,7 @@
         /// </summary>
         public uint Signature { get; set; }
 
-        /// <summary>
+        /// <summary>s
         /// Unknown (Entry count?)
         /// </summary>
         /// <remarks>
@@ -27,12 +29,14 @@
         /// <summary>
         /// Version, always 8 bytes?
         /// </summary>
-        public string? Version { get; set; }
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string? Version;
 
         /// <summary>
         /// Unknown (Build? Formatted as a string)
         /// </summary>
-        public char[]? Build { get; set; }
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
+        public char[]? Build;
 
         /// <summary>
         /// Unknown (0x14h), Variable number of bytes before entry table
diff --git a/PortableExecutable/SecuROMAddDEntry.cs b/PortableExecutable/SecuROMAddDEntry.cs
index e6e6f67..63c9828 100644
--- a/PortableExecutable/SecuROMAddDEntry.cs
+++ b/PortableExecutable/SecuROMAddDEntry.cs
@@ -64,7 +64,7 @@ namespace SabreTools.Models.PortableExecutable
         /// Entry file name (null-terminated)
         /// </summary>
         /// <remarks>12 bytes long in the sample (all 3 entries) in 4.47.00.0039</remarks>
-        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 12)]
+        [MarshalAs(UnmanagedType.LPStr)]
         public string? FileName;
 
         /// <summary>