These disk images were created with WinImage 8.1. I initially encountered read errors when attempting to image disks 2 and 3, so I resorted to manually archiving the contents. As a result, disks 2 and 3 now have file access timestamps. I then unchecked Ignore Empty Tracks in WinImage, and I was able to get disks 2 and 3 imaged without any read errors.