Looks like a really nice game. Take care of it and it will last another 30 years. A few comments and suggestions – First, get that battery off the MPU. It’s already corroding. Replace it with a remote battery or NVRAM. barakandl (nvram.weebly.com) has nice NVRAM.
Since the previous tenants dined on the wiring, transformer, and other stuff, closely inspect everything. Make sure the wiring is properly insulated. I don’t think the electrical tape is going to cut it. Heat shrink tubing is best. I have used liquid electrical tape for small areas but you need to give it several coats. See this thread:
Next tip – when you lean the playfield back into the backbox you might want to lay a towel over the backbox to prevent scratching any surface.
Also be sure all your connections are good. You may want to read this thread:
Good luck with your new game.