I think that game is a perfect candidate for hotter coils. You've got 4 flippers working off two coils, and you've got those weird long metal linkages operating the upper set. You can't get replacement parts for anything in that system, and there's no way it operates as smoothly as it did new. In that case, I think slightly hotter coils make up for 60 years of wear and help you get the game back to the way it did when it left the factory.

I put them in Pinwheel and 4 Stars, both machines with the two pairs of flippers side by side at the bottom, and it doesn't feel like the machines have been jacked up, but they do seem to play a little smoother.

If we're being honest, I think the hotter coils are a placebo more than anything.

You take the flippers all apart, you clean everything, you replace the nylon bushing at the playfield, and the bakelite linkages, put new nylon sleeves in, re-do all the solder joints, and finally clean and adjust the return springs and all the switches, and low and behold, the flippers work better!

Well, they probably work better because you did all that maintenance on them more than because you put different coils on, the new coils were just what finally motivated you to do it all.