Gaskets protect the movement, dial and hands from water and moisture.
When servicing a watch, if we have gaskets of the same size as the genuine one, we can easily replace it with a new one.
However, the crown gasket is not replaced every time.

The manufacturer’s service center can replace the entire crown to maintain water resistance (in this case, the crown will be a service crown).

So what if the crown gasket has worn out on vintage watches?

The crown has a lid to hold the gasket.
First, remove it.

Then it needs to remove the gasket and clean the inside. A gasket that has been stored for a long time hardened like plastic or melted like jam.