If the pin reset motor is running all the time check the contacts that are on the motor it self. There should be one that acts like a cam on that motor. If its closed it will keep running. that or it could be further up the chain. That or the armature is not releasing and it is coasting past the stop point and starting again.

That would be a neat way to hide a gun in plain sight. Have some sort of quick release on it. Like some kind of spy movie.

Looks don't matter as long as the game works. Good job.

When I build my model railroad I will incorporate that bridge somewhere.