Yeah I like the classics just as much as the newer stuff, but I spent my whole childhood in the arcades so I have countless memories of playing arcade games so I'm especially partial to the classics. Some of my favorites include Marble Madness, Karate Champ, Ka-Ge-Ki, Elevator Action, Tron, and on and on. The red ball top joystick in the middle actually is a dedicated 4-way. I had to have one for those older games.
As for the panels being swappable, what I'm going to do is make some jigsaw cuts along the pencil lines you can probably see in the picture so the panels will pull straight out, and I'm going to drill a few holes along the top cut and insert some dowels into the fixed portion of the CP top and glue them in, and drill matching holes in the removable section so it will line up, and likewise I'm going to use dowels to connect and align the two removable panels side by side. Then I think I'll use some kind of cabinet latches on the underside to lock them in place. I'll post some more pictures once I get everything cut and working like I plan. I think it will be easier to understand by looking at it. I also bought some male and female DB9 connectors which I'll solder the wires to so the harnesses for the joysticks and buttons can be unplugged when they're removed, and whatever is going in can just be plugged in. I'm still working on it so expect more pictures soon.