I wonder if the reset button has now to small on the inside so when you now reset the pusher does not go in far enough so it maybe just this. I don't know the model but I guess it is a 7750 based movement or do you know what you have. If it is the 7750 movement if you take the back off and see were the reset pusher is connecting to the movement and either put a spacer in to test the theory or try pushing the return bar in. The hour wheel is a disc the is fitted to the normal hour wheel

Richard

PS if not can I see a picture as this would help me