Myself I have a friend that sells old slots and he has aquired a large amount of spare parts from other slots he has bought and weren't worth repairing so he strips them for good parts, he is always going to a large warehouse in Reno and buying slots that have come out of the casinos, I belive he has around 150 slots at the present time.
Walt
P.S. He never was able to get any of the old style Silver Strike machines and he belives IGT destroyed them as they got them back. That was a shame as I would have bought one of the old machines to have.