Congrats Pecos, along for the ride! This reminds me that I still need to order a schematic for this game.

He is especially proud of the circuit involved with the ball return from the gobble holes.

Novus 2 ordinarily works wonders on plastics, but the formula for plastic was not the same then as it was in the 70s or even the 60s. The older the game, the worse it gets, with bumper bodies and posts collapsing in on themselves.

Testing any cleaner will be fine, but you can't reverse the goo-ifying/shrinking process. So, as has been said, they will only get but so clean if you keep original.

For anyone that might be interested: I've reviewed the circuit on my copy of the schematic! It shares quite a bit in common with the scoring circuits in the bingo pinballs.

Between the design of the circuit and the physical layout, it is indeed something to be proud of - no EMI causing false switch closures is pretty darn impressive. Also that the ball can roll down with speed and it will trigger each of those switches at the appropriate time.

I am curious if there will be some fine tuning of these switches once you are in testing mode, or if it is pretty tolerant to minor variations in switch tension.