The only thing I would add to the excellent advice above is that you should find out whether the balance staff is good or not before selling. Giving prospective buyers this information usually makes a substantial difference in the selling price.
To check: With the back open so you can see what is happening, shake/twist the watch gently. One wheel (the balance wheel) should spin back and forth with free motion and gradually cycle down to a stop if it is working as it should. If nothing moves, or if the balance moves, but only a little and not freely, the balance wheel staff is most likely broken. If it moves freely, check it in a couple of different orientations (dial up, dial down, etc.). If it moves about the same in all of them, it is definitely good.
This is a fairly expensive but routine repair, and hardly a deal-breaker on value, particularly for an uncommon watch such as yours. Maybe half of the watches out there being sold as non-running have broken balance staffs. As a buyer, I assume every non-running watch I buy has a broken staff unless told otherwise.
If the balance staff is good, the value of the watch is substantially higher, even though it doesn't run. Even if it is known to be bad, buyers will know what is wrong and have more faith in your description, so the watch may sell for more.
Whatever you do, though, don't stick anything into the movement to try to make things move or try to make the balance spin!
Addendum:
Also you should check whether the mainspring is broken or not. (This is the second-most-common cause of non-running watches in good shape, after the broken balance staff.) The crown can be turned in two directions: one winds the watch; the other does nothing at all. You can tell which direction is which by looking inside. When the watch is winding, the big wheels turn, and when it isn't, they don't. If the watch will not wind in the winding direction, or if it will wind, gets tighter, and eventually stops winding, the mainspring is good. If it winds forever without stopping, the mainspring is broken. Watches with broken mainsprings don't run. This is quite a cheap repair, and quite simple to test for!