Historical signicicance aside, the big problem I see with Mame-ing that cab is that is just is not a fun cab to play on for most games. You have a tiny screen, hyper-angled control panel, and I think it would just feel funny playing TMNT on a cab like that. To me, the whole thing would feel as dirty as a $2 whore.
I know there was a thread here earlier about a dude who mamed his Computer Space, and he did about as much justice to it as feasibly possible. You can search for that thread to see how he did it. He made the same argument. He loved the thing but it was just a shell. It would cost too much to have it restored. I was pretty much on the fence about it, cuz I know cost is a big issue for most of the population, and when people were telling him to sell the cab off or give it to a collector, I never felt there should be any obligation of an owner to do that.
The best Idea I remember hearing, I think, was from Chad. He mentioned that it might just be the most economical to program a clone of computer space and run it on the machine through a tv mounted in there. I have never played the game, but I figure it has to be one of the easiest games in the world to program.