I think I've seen pictures of that machine. It looked complete and had a few things in the cabinet that weren't original that can be tossed....like a motor-driven cam unit (the motor had "murten/schweiz" on it).
the only plastic-coated wires in the game originally were in the 115V circuit. There probably weren't any relays originally in the cabinet (not counting the one on the playfield bottom), so you may have some spare parts.
the wire bundle for the back door and lamp panel didn't look that bad before, but it was partially unbound. I guess someone took it apart further to chase wires. You can probably get it more-or-less neatly back together just from the picture xsvtoys posted above.
the relays, switches, coils, etc. are all standard parts used in bingos and flipper games of that era. You've even got a newer style motor in there that is capable of 50Hz. The only time you may be mildly concerned is when stepper units or wiper assemblies are missing ... those take more effort to find something the same or close enough to make work.
you typically don't look for new parts. There's plenty of parts games with pieces in good condition, so once you've got the wood taken care of and the game reassembled, post pics of things that are broken/missing/worn out and people with parts can see what they have for you.