But you can't have it legally on your home built MAME machine (at least with EVERY game you could think of). The various MAME cabinets that you see in arcades get most of the popular ones though, and you can buy those machines.
Buying old broken machines allows you to do a full restoration, exempting hardware, that flawlessly plays classic games. When you buy the machine with the ROMs, or a machine from an owner you bequeaths you all rights including his right to all information on the ROMs all lost parts, et cetera, then get the right to run the game. You can buy a crapped out box and gain the legal rights to a full restoration in a commercial or private environment. Someone could probably make a hand-some amount of money selling replica machines with the rights they gain. One could even secure the old ROMs inside a new case as proof of its legality. Emulation has made it so some of the very fun cult classics could make their way back into bars, or even in gamer cafe's. One game on a machine, period. Mastering a really hard game makes one want to play more. Anyone who has ever played Defender:Stargate understands the urge to pump in more quarters to get a shot at them Yllabians.
This would be awesome. Simply set up a web page where people can donate to help you carry out your messianic duties, sit back, and collect a shit load of cash.
It would be no worse than what the fifty churches in my town do. Plus instead of using the money for purely evil reasons you could do the world favor and donate it to the ACLU, Richard Dawkins Foundation For Reason and Science, the Reason Project, or cancer research. There are a millions things that could be done with that money, after taking a hefty sum for yourself, of course.
An authority is a person who can tell you more about something than you really care to know.