I'm looking at converting Vs. Dr. Mario (MMC1) to use a VRC1 or "VRC1 like" instead. I've looked at Vs. Dr. Mario and the banking code seems pretty easy to follow. I think, I don't know for sure, that the the PRG code probably has $C000 fixed which from my understanding from the wiki makes it easier to convert. The CHR part I'm not as sure about. The graphics stuff never seems to get through to me.