If it's the original crown, you could find an old 24-700 crown and install it. If you have a later replacement assembly (24-702 or 24-703), it's easier to get parts. When the crown on my 1680 (24-702) did what yours is doing, my watchmaker swapped out for the newer 24-703 crown and tube. Since then I've come up w/ a 24-702 crown and may go back to that assembly at some point ince that was what was in there originally.