A while back I bought one of MacRories R-Time 8 (the long board version, in a case). Not the drop-in replacement. His case didn't work out for me, so I decided to come up with a new design that's compatible with all of the 8-bit Atari models including the Atari 1200XL, and a properly functional shield'd hat. The shield as we all know prevents a cartridge from being inserted backwards...
Here are some renders of what I've come up with.