I fixed the score reel not resetting .. dirty and slightly out of adjustment 9th position switch on the reel . Both manual and schematic are wrong which game me a bum steer.
They say reels are reset via 0 position switch, but in fact its the 9th position switch.
These 42 year old wire colours are pretty faded too.

Seems like I have one weird fault left , which is on 5th ball in 2 player game, machine resets player1 card count at end of player 2 5th ball, and gives player 2 another ball, then goes to game over when that ball drains. I think that one will prove tricky to track down.