Here is a thread I have been following that is going through a ball bowler but most mechanisms are the same.

https://pinside.com/pinball/forum/topic/reviving-a-1963-united-sabre-ball-bowler-

Also a little confused, physically the relays are missing and it use to reset. Wow.

Also Mopar seems to know his stuff. I believe like I’m sure you read You have to clean up and lube all s.u. And d.u. Anything sticking could prevent a restart. I noticed the one scorer was at 1. Has it been like that maybe manually reset it to 0. I have a cape cod 72’ United works pretty good just need to finish going through the s.u. For spare and strikes , frames and score reels. I cleaned switches on the alley took apart and lubed with a Teflon grease and de-rusted parts then cleaned the pin deck all mechanisms the same. As you clean parts thing starts to come more alive.