Back to this watch, it is much more common to see cases were the sleeve threads into the neck of the case, as a separate part and there is no cap piece.
But stems and sleeves are a topic for another day. This watch has an interesting problem related to the crown. At some point it appears that the crown has been replaced with one that is not going to work.
The crown threads down on the stem. Pulling and pushing the crown thus moves the stem in and out. The bottom of the crown will, or should, come near to hitting the top of the cap on this case. That would be the most the crown can be pushed down. And that needs to be far enough for the stem to snap, and press into the movement far enough to engage the winding mode. But this crown hits the cap too soon and can not be pushed down far enough to snap into winding position. This was the owner's complaint - the watch seems "stuck" in setting mode.
To solve this problem the crown needs its inside cut back so that is will go down further before coming to the top of the cap and being stopped. To do this we use the lathe and a special crown chuck. This chuck is basically a cup with an assortment of different sized threaded caps that hold the crown down in place against a pad inside the cup. The caps are open-ended, exposing the crown.
Here we see the crown placed into the crown chuck. The bottom of the crown is exposed.
Here see see the cut done. Compare this to the photo above. The shine of the freshly cut area can be seen inside the crown. The crown will now travel down over the top of neck of the case far enough that the stem will snap the key-less works of the movement into winding mode.
The watch is now ready to go, setting and winding working fine, ready to tick off countless days to come.