Ok, I've been asked about this a few times recently, and without further ado, please excuse me if you've read this before, or if you already know this, or have heard me go off about this elsewhere.
I'll spare you all my usual rant about watch services, and just deliver a cautionary post.
Mechanical watches in general need to be serviced every 5-8 years, even if they are not worn. Lubricants dry out. Running a dry watch can wreck it, as can running a dirty watch. You can't lubricate a dirty watch. Every service, or overhaul should include a complete disassemble and cleaning in the proper fluids (no ultrasonic) with lubrication with modern lubricants followed by regulation. It's more involved than this simple description, however.
I have serviced many watches from the 'Bay, given to me by customers who tell me the watch was advertised as recently serviced. I have never found this to be the case. I always find a dirty or dried out dirty watch, even from extremely reputable dealers and publishers of well known reference books who oughta know better. No names, no pack drills.
In short, if you don't know when your vintage watch was last serviced, don't run it until it is, as it can easily cause irreparable damage. It only took me three months to totally destroy an NOS dive watch I got at a Flea Market. This was before I went to watchmaking school, and I was able to repair it when I was there. It was an excellent example of what can happen just using a watch day to day without proper maintenance.
So, I know we all (and I included) want to show off the latest aquisition on the wrist, but it is critical to ensure the watch is properly serviced before running it for any length of time. I know it's an additional expense, but I believe it is worth it, after all, we are here to celebrate and preserve the past.
Btw, this is not directed at anybody, just a general public service announcement from your friendly neighbourhood spi-... er.... watchmaker.
Well said Rob. I try to disassemble all of my watches to clean them and use a special non-water based cleaner I have been testing for a few months and then put them back together but don't have the knowledge or equipment to due the really good regulation so mine is a longer process of adjust and test and adjust and test until I am satisfied the watch is as close to running at the correct timming. So far, it has worked out well but I am sure it will eventually bite me in the fanny.