How is the stepper unit for the credit wheel? If it moves too slow, it will decrement more than one game. I’ve seen them decrement from 15 to 0 when the stepper movement is not crisp or the pawl is slow.

You probably need to clean the stepper unit.

Welcome to Pinside. I think the Replay Reset Register solenoid is what subtracts credits from the four digit credit counter. Is that right? If so you might try blocking (with bits of paper) switches in the two main circuits that drive that solenoid, like the cam switches in the red boxes. If blocking one of those switches results in the expected single credit subtraction that might help narrow in on the problem.
Miss America 75 replay (resized).jpg
Also, does the number of credits subtracted match the number of games added to the Total Play Meter? If not there might be a mechanical issue with the credit counter rather than an electrical issue.

/Mark

Have you observed whether the Red Button relay stays active longer when the problem happens? I think once the Red Button is pressed to activate the Red Button relay, the relay should stay active until the cam switch in the red box opens.
Miss America 75 Red Button relay (resized).jpg
If the Red Button relay stays active longer than it should it might be because that switch isn't opening reliably.

I think this is the Start relay lock in circuit. You might check the cam #3 switch to see if it opens reliably.
Miss America 75 Start relay (resized).jpg
If you haven't already you might want to read through this site:
https://bingo.cdyn.com/techno/howtheywork/
and in particular this section:
https://bingo.cdyn.com/techno/howtheywork/reset/start.html
It was written by someone who understands these much better than I do.

Bart ik ben bang dat de het slot waar de Timer index coil onder de Control Unit elke keer in moet vallen iets uitgesleten is. Dan stopt de CU even maar gaat vrijwel meteen weer door, waardoor het start relais wordt bekrachtigd. Hierdoor lijkt het alsof de machine weer opnieuw start. Het kan ook zijn dat de frictie op de koppeling van de Control Unit te zwaar is waardoor de Timer Index coil gewoon niet genoeg kracht heeft om de Control Unit te stoppen.

Ik zag je Miss America op Marktplaats staan. Daar geef je aan dat ie prima in orde is. Iets anders dan je hierboven beschreef toch?