Quoted from pinhead52:
there other thing too to look at, are the jones plugs inserted correctly? Most games have two plugs from the bottom into the head. A small number of games have plugs with the same pin count on the two plugs leading to the two connectors in the wrong sockets... always good to validate wire colors on 3 or 4 of the leads on either side of the coupling.
We are here to help and will try not to bite your newbie head off
Great leads! 15A fuse for backbox lights was clearly blown - replaced it, played, and no further issues with the fuse, but still no lights. Unplugged/cleaned/replaced backbox jones plugs (there are 3 main ones, all different sizes). Tiny bit of progress - 3 of the lights now work. Inspected a few other random bulbs and they are either burned out or dodgy looking, so I'll replace all of those. I assume some electrical issue in the unit's past would explain the fuse and possibly the numerous blown bulbs. Hoping I'm on my way. Thanks again for indulging a newbie!