The big problem with those isn't the wiring, it is that they don't make a mounting plate for them.
I'm pretty sure they use the same optic boards as the smaller trackballs, so you can get harnesses for them from Oscar, if you want to.
They mounted straight to the metal CP on the Atari Football games, Missle Command Uprights, etc...
Happs site says "mounting hardware sold separately", but I've never seen the hardware on their site anywhere.