Nope, not Software. Just Fools.
You are correct about the origins of the MMtC kit.
https://public.fotki.com/drasticplasticsmcc/mkiba-build-under-c/amt-instructions/show-rods/amt-xr-6-27-t--ford/
https://public.fotki.com/drasticplasticsmcc/mkiba-build-under-c/amt-instructions/tv--movie/amt-my-mother-the-car/
The MMtC added a Set of 3 new Hood Parts, a Radiator, and spacer to mount it on, a Radio, an a 5 piece Gas Tank and Base, and a Trunk. Not much else is changed.
Close examination of the instructions shows most of the kit is a straight carry over.