I just picked up a rather nice 1900s Elgin wrist watch with a 0s movement. It may be a pocket watch conversion, as I can't find any Os movements intended for wrist watches. It does have the crown at the 3 position. But the (quite common?) dial is covered in cracks. It seems to keep time fine...

I have my original 218 that I'm having cleaned & lubed. I want to keep that one original. I also picked up, floating on the Bay, three watches in a batch one of which is a 218 (2180 no day or date) and isshown herein. They were $35 and the other two are like new and the Pulsar is gorgeous...