I updated our listing just now with a modest bit of info. Not enough to help you, sorry. If you can, try to get a focused close up of the metal Inspection Plate that should be affixed to the upper left corner of the playfield. If not there, then somewhere on the cabinet, maybe. It looks like this:
https://www.ipdb.org/showpic.pl?id=4610&picno=55200
It can tell us stuff. Then please shoot me an email as I was just passing by this thread and may not be back if you were to post it only here.
Thank you.