I remember dropping in on a place that specialized in restoring old pinball machines oh say 10 years ago? They were just REALLY starting to pick up back then and already were swamped with work they were telling me. Some of their restorations were going for like 10k+$... They were also restoring one of those electromechanical dog racing games for a casino. Honestly if anyone wanted a job in working with these things there's probably really good demand for skills.