I would have absolutely no reason to have more than one game list. There are only like 20 roms on the thing in the first place. I skipped out on a lot of the vertical games, just used the horizontal tball games and Tempest, Millipede, and Centipede.
I think I am going to need a few admin buttons anyway. There are a megaton of suitable PC games that I could add if I just had enter and escape buttons. Just going to put them all inside the cashbox door (lower of the 2 coin doors). I also plan on making the coin reject button trigger a switch, and possibly hooking up the bill acceptor (it seems to work).
Another possible place for admin buttons is on the back door. The cabinet is small enough to reach around back and slap a button.
Finally, an option would be to put all those lockbar holes to good use, and add a small box over them on one side with buttons on it.
I am REALLY tempted to add a 4-way joystick and 2 more buttons to this thing. But I also REALLY don't want to alter the panel. Good thing I don't have a 1 1/8th metal holesaw around, otherwise I probably would have already done it. Doing that would mean I had all 4 major Mame cabinets. (8-way horizontal, 8-way vertical, 4-way vertical, and 4-way horizontal). I also considered adding that Tac/Scan spinner that I had, but I can't get the darn thing off the panel it is on.