On almost every game I have owned/restored, I have found the score reel coils 'gunked up' with an operator's attempt at 'maintaining' them....... Good comments above, would certainly clean up the whole thing. I have also found burned spots at times on the circuit boards that control match/high score awards. Areas to lube include the contacts on the circuits, axles with moving parts, and I sometimes add a bit behind the advance arm where it slides against the metal frame.