Ok, my Heuer Monnin needs a crown with the correct tubing/gasket... my watch specialist, said I can do one of two things the first is finding a correct 844 crown with correct tubing/gasket.. or he was wondering this do any of you know of a way to take the original crown and covert it with materials available today? If so can you provide me with details on how? like size or what he'll need? He said he can do it but would like to make sure he can choose the correct modern materials to make the crown good again, I saw the crown and it looked ok in fact I thought all he needed was to insert a gasket, however, since this is a diver I'm assuming there is more to it than that (watchmaker talk).

Please let me know.

~George