These images were compiled with a old version of the command line maxflash kit. They were made using the -diskpacker option which replaces the OS disk read routines with cartridge read routines.
Any image created with the -diskpacker option will require 64k, since it needs the ram under the OS to replace the OS. At some point I added a on-screen message for carts that require 64k, but these images don't have it.
All the games in these images should be available as XEX files, so you can compile a new cartridge by just going to file->new and then adding the xex images. You should be able to get most of these titles here:
http://ape.dyndns.org:8084/Steve