Winder crown has come off

[Gkirkby@aol.com]

I have my father’s 1939 ( year) Rolex oyster. I was winding it recently and the crown came out and in fact, right off. There seems to be a short tube attached to it with a tiny spring inside. I’m presuming the tube should be a lot longer to engage with the winding mechanism inside so I guess it ( the tube) has snapped.
Has anyone had a similar experience and if so what was the cure?
Thanks