Thanks for doing this for the community! I would like to comment on my experience when I built my own rotisserie (similar concept). It was all good and well until It was time to install the rear wood panel. With the rear panel and the side rails installed it becomes really difficult to secure the playfield with the C-clamps. It gets worse when you start populating the playfield back there with all the ball guides and stuff and all the wiring, lamp sockets and stuff back there. The Angle iron would not allow me to mount stuff back there too.
All games are different of course. The game I restored was Indiana Jones. The only way for me to secure the populated playfield was to clamp it down from the side rails and the C-clamp would barely catch the rear rotisserie mount. I had to protect the brand new side rails with rags and stuff. Would it be possible to do some sort of clamp that secures the playfield from the sides? That would be very helpful when the playfield is populated and the rear panel is installed. Thanks!