Well I managed to defeat the torx bit using a small flat bladed screwdriver. I got into the back of the final cab and unscrewed the front locks from the inside. The cab with the vertical screen had a 60-in-1 in it (boo!). The 60-in-1 works fine, so I guess that's a bonus. It also had an old Neo Geo board that was not hooked up. The board doesn't boot (double boo!), it just stalls at the green boot screen. The game cart in that board was Super Sidekicks 2 (triple boo!). I tested the cart in the working Neo Geo board in the other cab, and it works. Still, it's a soccer game, so no one cares
A lesson in not siting your stuff in kids' rooms This is what I just cleaned out of the back of one of the cabs. No idea how they managed to get so much chalk in there.