Joezy, I am concerned you might not be working towards an offer of code contribution.
Unfortunately I never had any contracts offering me royalties on future republished or derivative works unlike some of my peers. Not that they could claim any these days, anyway. But I think it still should be put in the discourse for posterity.
MAME has thousands of ROMs and games, it would be near impossible to get a license to sell each and every ROM.
StarROMs tried that with the Atari arcade ROMs but failed.