Welcome to the club!
The sites I use when I need info are mostly Pinside and Facebook (Pinball Enthusiasts group and the Pinball Repair Help!! group).
The Data East Pinball Club and the BTTF Club here on Pinside might be worth reading and following
https://pinside.com/pinball/forum/topic/data-east-pinball-club/page/39#post-5686704
https://pinside.com/pinball/forum/topic/bttf-club-whoa-this-is-heavy/page/8#post-5321654