In 1986-88 I used to work at an arcade that also shopped outside locations and had quite the collection of pinballs, ranging from 70s electromechanicals, to the early digital machines to the state-of-the art pins (at that time Premier's 'Gold Wings' was a new machine)

I remember the early (70s and 80s) Stern machines were like the AMC (car not theatre chain) of pinballs: they used Williams coils and pop bumper covers, Bally neon displays, and Gottlieb and Williams flippers...

I did my share of shopping out pinballs, replacing dead coils and switches, waxing playfields, cleaning backglasses and topglasses, repairing broken coin mechs, changing the hundreds of light bulbs.... etc... Didnt do too much to the electromechanical machines except for playfields and bulbs, the owner of the place was an expert on the older machines. Had a Williams 'Disco Fever' topglass literally explode in my hands (thermal shock, I believe) as I was removing it top service a playfield. Glass everywhere! If I had the room for a pinball I'd have gotten one when the operator gave me a kickback for getting him some theatre locations back then. Instead, I took a jukebox