Pre-internet you just wrecked decent machines to keep your better ones going, it didnt really matter because pins were in garage sales/sat paper's for-sales column every weekend. We had a shed full of machines in the 80's, 12-15 to play, and 10 or more wrecked to keep them going. Good pin could be purchased for 50 fair to 200 bucks for near mint one back then. I dont have dads collection, but I have great memories of it!
Greg,
Do you have any photos from those times?