diff --git a/app/ACUArchive.cpp b/app/ACUArchive.cpp
index 727836f..44122fd 100644
--- a/app/ACUArchive.cpp
+++ b/app/ACUArchive.cpp
@@ -212,9 +212,7 @@ int AcuEntry::ExtractThreadToFile(int which, FILE* outfp, ConvertEOL conv,
     SET_PROGRESS_BEGIN();
 
     /*
-     * Generally speaking, anything in a BNY file is going to be small.  The
-     * major exception is a BXY file, which could be huge.  However, the
-     * SHK embedded in a BXY is never squeezed.
+     * Generally speaking, anything in an ACU file is going to be small.
      *
      * To make life easy, we either unsqueeze the entire thing into a buffer
      * and then write that, or we do a file-to-file copy of the specified
@@ -383,7 +381,7 @@ GenericArchive::OpenResult AcuArchive::Open(const WCHAR* filename,
 {
     CString errMsg;
 
-    fIsReadOnly = true;     // ignore "readOnly"
+    //fIsReadOnly = true;     // ignore "readOnly"
 
     errno = 0;
     fFp = _wfopen(filename, L"rb");
@@ -740,6 +738,9 @@ void AcuArchive::AcuConvertDateTime(uint16_t prodosDate,
 
 bool AcuArchive::TestSelection(CWnd* pMsgWnd, SelectionSet* pSelSet)
 {
+    // TODO: this is essentially copy & paste from NufxArchive::TestSelection().
+    // We can move the implementation to GenericArchive and just have an
+    // archive-specific TestEntry() function.
     NuError nerr;
     AcuEntry* pEntry;
     CString errMsg;
diff --git a/app/ACUArchive.h b/app/ACUArchive.h
index 55ed20d..3aca48d 100644
--- a/app/ACUArchive.h
+++ b/app/ACUArchive.h
@@ -4,7 +4,7 @@
  * See the file LICENSE for distribution terms.
  */
 /*
- * AppleLink Compression Utility archive support.
+ * AppleLink Compression Utility archive support (read-only).
  */
 #ifndef APP_ACUARCHIVE_H
 #define APP_ACUARCHIVE_H
@@ -33,11 +33,14 @@ public:
     virtual long GetSelectionSerial(void) const override { return -1; }
 
     virtual bool GetFeatureFlag(Feature feature) const override {
-        if (feature == kFeaturePascalTypes || feature == kFeatureDOSTypes ||
-            feature == kFeatureHasSimpleAccess)
-            return false;
-        else
+        if (feature == kFeatureHasFullAccess ||
+            feature == kFeatureCanChangeType ||
+            feature == kFeatureHasInvisibleFlag)
+        {
             return true;
+        } else {
+            return false;
+        }
     }
 
     /*
@@ -60,7 +63,6 @@ private:
      */
     NuError CopyData(FILE* outfp, ConvertEOL conv, ConvertHighASCII convHA,
         CString* pMsg) const;
-    //NuError BNYUnSqueeze(ExpandBuffer* outExp) const;
 
     AcuArchive* fpArchive;      // holds FILE* for archive
     bool        fIsSqueezed;
@@ -73,8 +75,7 @@ private:
  */
 class AcuArchive : public GenericArchive {
 public:
-    AcuArchive(void) : fIsReadOnly(false), fFp(NULL)
-        {}
+    AcuArchive(void) : fFp(NULL) {}
     virtual ~AcuArchive(void) { (void) Close(); }
 
     /*
@@ -102,7 +103,7 @@ public:
     virtual CString Flush(void) override { return ""; }
 
     virtual CString Reload(void) override;
-    virtual bool IsReadOnly(void) const override { return fIsReadOnly; };
+    virtual bool IsReadOnly(void) const override { return true; };
     virtual bool IsModified(void) const override { return false; }
     virtual void GetDescription(CString* pStr) const override
         { *pStr = "AppleLink ACU"; }
@@ -158,7 +159,7 @@ private:
             fclose(fFp);
             fFp = NULL;
         }
-        return "";
+        return L"";
     }
     virtual void XferPrepare(const XferFileOptions* pXferOpts) override
         { ASSERT(false); }
@@ -185,12 +186,12 @@ private:
     /*
      * The header at the front of an ACU archive.
      */
-    typedef struct AcuMasterHeader {
+    struct AcuMasterHeader {
         uint16_t    fileCount;
         uint16_t    unknown1;       // 0x01 00 -- might be "version 1?"
         uint8_t     fZink[6];       // "fZink", low ASCII
         uint8_t     unknown2[11];   // 0x01 36 00 00 00 00 00 00 00 00 dd
-    } AcuMasterHeader;
+    };
 
     /*
      * An entry in an ACU archive.  Each archive is essentially a stream
@@ -200,9 +201,9 @@ private:
      * We read this from the archive and then unpack the interesting parts
      * into GenericEntry fields in an AcuEntry.
      */
-    struct AcuFileEntry;
-    friend struct AcuFileEntry;
-    typedef struct AcuFileEntry {
+    //struct AcuFileEntry;
+    //friend struct AcuFileEntry;
+    struct AcuFileEntry {
         uint8_t     compressionType;
         uint16_t    dataChecksum;       // ??
         uint16_t    blockCount;         // total blocks req'd to hold file
@@ -225,7 +226,7 @@ private:
         // possibilities for mystery fields:
         // - OS type (note ProDOS is $00)
         // - forked file support
-    } AcuFileEntry;
+    };
 
     /* known compression types */
     enum CompressionType {
@@ -291,7 +292,7 @@ private:
         uint16_t prodosTime, NuDateTime* pWhen);
 
     FILE*       fFp;
-    bool        fIsReadOnly;
+    //bool        fIsReadOnly;
 };
 
 #endif /*APP_ACUARCHIVE_H*/
diff --git a/app/GenericArchive.h b/app/GenericArchive.h
index b44f0dd..8ab0f32 100644
--- a/app/GenericArchive.h
+++ b/app/GenericArchive.h
@@ -39,13 +39,13 @@ const int kFileTypeBAS = 0xfc;
 /*
  * Set of data allowed in file property "set file info" calls.
  */
-typedef struct FileProps {
+struct FileProps {
     uint32_t    fileType;
     uint32_t    auxType;
     uint32_t    access;
     time_t      createWhen;
     time_t      modWhen;
-} FileProps;
+};
 
 /*
  * Options for converting between file archives and disk archives.
@@ -117,16 +117,16 @@ public:
         kAllowDamaged = 0x80,
     };
     /* EOL conversion mode for threads being extracted */
-    typedef enum ConvertEOL {
+    enum ConvertEOL {
         kConvertUnknown = 0, kConvertEOLOff, kConvertEOLOn, kConvertEOLAuto
-    } ConvertEOL;
-    typedef enum EOLType {
+    };
+    enum EOLType {
         kEOLUnknown = 0, kEOLCR, kEOLLF, kEOLCRLF
     };
     /* high ASCII conversion mode for threads being extracted */
-    typedef enum ConvertHighASCII {
+    enum ConvertHighASCII {
         kConvertHAUnknown = 0, kConvertHAOff, kConvertHAOn, kConvertHAAuto
-    } ConvertHighASCII;
+    };
 
     /* ProDOS access flags, used for all filesystems */
     enum {
@@ -138,8 +138,12 @@ public:
         kAccessDelete       = 0x80
     };
 
-    /* features supported by underlying archive */
-    typedef enum Feature {
+    /*
+     * Features supported by underlying archive.  Primarily of interest
+     * to EditPropsDialog, which needs to know what sort of attributes can
+     * be altered in the file type and access flags.
+     */
+    enum Feature {
         kFeatureCanChangeType,
         kFeaturePascalTypes,
         kFeatureDOSTypes,
@@ -147,7 +151,7 @@ public:
         kFeatureHasFullAccess,
         kFeatureHasSimpleAccess,    // mutually exclusive with FullAccess
         kFeatureHasInvisibleFlag,
-    } Feature;
+    };
 
     /*
      * Extract data from an archive (NuFX, disk image, etc).
@@ -384,13 +388,13 @@ public:
         return fNumEntries;
     }
 
-    typedef enum {
+    enum OpenResult {
         kResultUnknown = 0,
         kResultSuccess,         // open succeeded
         kResultFailure,         // open failed
         kResultCancel,          // open was cancelled by user
         kResultFileArchive,     // found a file archive rather than disk image
-    } OpenResult;
+    };
 
     // Open an archive and do fun things with the innards.
     virtual OpenResult Open(const WCHAR* filename, bool readOnly,
@@ -410,13 +414,13 @@ public:
     virtual void ClearReloadFlag(void) { fReloadFlag = false; }
 
     // One of these for every sub-class.
-    typedef enum {
+    enum ArchiveKind {
         kArchiveUnknown = 0,
         kArchiveNuFX,
         kArchiveBNY,
         kArchiveACU,
         kArchiveDiskImage,
-    } ArchiveKind;
+    };
 
     // Returns the kind of archive this is (disk image, NuFX, BNY, etc).
     virtual ArchiveKind GetArchiveKind(void) = 0;
@@ -465,9 +469,9 @@ public:
         const RecompressOptionsDialog* pRecompOpts) = 0;
 
     // return result from XferSelection()
-    typedef enum {
+    enum XferStatus {
         kXferOK = 0, kXferFailed = 1, kXferCancelled = 2, kXferOutOfSpace = 3
-    } XferStatus;
+    };
 
     // Transfer selected files out of this archive and into another.
     virtual XferStatus XferSelection(CWnd* pMsgWnd, SelectionSet* pSelSet,
@@ -495,7 +499,7 @@ public:
 
     // Determine an archive's capabilities.  This is specific to the object
     // instance, so this must not be made a static function.
-    typedef enum {
+    enum Capability {
         kCapUnknown = 0,
 
         kCapCanTest,            // NuFX, BNY
@@ -506,7 +510,7 @@ public:
         kCapCanConvEOLOnAdd,    // Disk
         kCapCanCreateSubdir,    // Disk
         kCapCanRenameVolume,    // Disk
-    } Capability;
+    };
     virtual long GetCapability(Capability cap) = 0;
 
     // Get the pathname of the file we opened.
diff --git a/app/NufxArchive.h b/app/NufxArchive.h
index 1faa22c..6f61d59 100644
--- a/app/NufxArchive.h
+++ b/app/NufxArchive.h
@@ -35,9 +35,11 @@ public:
     virtual bool GetFeatureFlag(Feature feature) const override {
         if (feature == kFeaturePascalTypes || feature == kFeatureDOSTypes ||
             feature == kFeatureHasSimpleAccess)
+        {
             return false;
-        else
+        } else {
             return true;
+        }
     }
 
     /*