Ah, thanks for the note on the carriage bolts, I got the Happ controls today and noticed that my 1/4" bolts aint happening.
I am taking pix.

That's interesting about not needing the corners held down for the Lexan, that makes sense w/ all those buttons and joysticks holding things tight.. probably easier on the hand too so you don't hook it on the lower edges when playing.
I painted the front and sides black, and have sent off 3 designs to Kinkos for the overlay to pick up later.