A modern mechanical wristwatch is usually a current brand, with parts still in a supply chain and a service manual. A vintage pocket watch on this bench is usually out of production. Parts come from donor movements, old stock, or they are not available.

That is the real difference. It is not that old watches are better, or that new watches are disposable. A Hamilton 992B was a tool. A new mechanical wristwatch is often a luxury product with a warranty from the maker. I do not service current branded wristwatches under factory warranty. I service the vintage mechanical pieces, mostly American pocket watches.

Vintage also means the case may be gold filled rather than solid gold, the dial may be a later refinish, and the hairspring may already have been replaced. Those facts change the value. They do not always change the decision to make it run.

If the question is whether to service a family pocket watch or buy a new mechanical watch, those are different purchases. The pocket watch is worth servicing when the movement is complete and the parts can be sourced. If they cannot, I say so before taking the job. Photos go to the Services page.