If it hasn't been serviced in a long time, each time you wind it or let it run, it will cause small damage. The oils will have dried up long ago, and any dirt in the movt will grind against metal. Those who read my posts know that I myself destroyed a watch by simply winding it and running it, an old NOS dive watch. It took about three months to cause catastrophic damage to the point where wheels had to be replaced, etc. This is also assuming there are no hidden problems, like a cracked jewel, which will literally eat a pivot. Best to get it serviced by a watchmaker if you plan to run it. If you simply plan to sell it, just put it on the 'Bay with 'as is' in the description. If you search around pocket watch listings, you will get an idea of what they are selling for, checking finished auctions.