This machine is starting to do my head in. 
Have made some progress .. all PF lights now work (switch on tilt relay was out of adjustment)
Ball count unit was not stepping up due broken power wire on coil (not obvious)
One eject hole now works, the other still doesn't.
All PF switches now work.
Have tracked down some other switches which were out of adjustment causing other problems.
Still trying to fathom why it doesn't do anything when the ball drains and why only sometimes
it will reset and start a new game when using the credit button, but does when pressing the coin switch (which it shouldn't)
I also need to order 4 new coils for the pop bumpers as can't remove original sleeves.

I will get there , as usual it just requires patience and perseverance.