Join a pinball league and network.
Are you going to any pinball shows this year? There are pinball shows In Louisville, Nashville, Chicago, York PA, Allentown PA and a couple in Ohio. If you’re going to one of these shows look for a forum like the one below. Post what you are looking for and arrange a deal prior to the show.
https://pinside.com/pinball/forum/topic/2019-southern-fried-gaming-expo-for-sale-and-wanted-thread-