I spent some time this afternoon fixing up a few non functioning items on this game, ie two of the drop target banks, and i had a look at the display problems as well. I replaced the burnt 10k resistors on the master display, hoping it might fix the missing segment problems on players 1 and 2... well no such luck  it turns out that the display glasses themselves are crook, as the resistors i had just replaced started to burn again!! Pulling out the 1st and 2nd player displays and swapping them with the 3rd and 4th player displays stopped the resistors frying.  plugging the bad displays into the 3rd and 4th positions, they still had the same segments missing and were causing the 3rd and 4th player 10k segment resistors to heat up. So it looks like i'm up for a couple of new display glasses.

They look to be the same as the Stern/Bally 6 digit glasses.. can anyone reading this confirm this for me before i buy new ones??

I also removed and cleaned up the switch PCBs on two of the drop target banks to get them going.. im only doing enough at this stage just to get the game up and running, so i havent completely dismantled and cleaned the mechs yet.. i'll do this when i start the playfield restore, which wont be for a while yet.. I'll get it going and play it for a while first

Forgot to mention.. before any of the above was done, i fixed the coin/credit button switch problem which turned out to be dry jointed pin headers in the driver board for the switch matrix. i decided to replace the pin headers with new ones, since i had the board out.

For the top right target bank, which had its burnt coil disconnected, i quickly fitted and old coil of similar resistance to the good drop target coils.. again ONLY to get it going, i'll replace it with the correct one later. I also found it neccessary to replace the driver transistor for this coil to get the target bank resetting. I'm still having a few issues with the 4 target bank, not scoring sometimes, despite cleaning and adjusting the contacts.. fun & games