I am in the process of finishing up an overhaul on a Hamilton 931, S/N 47795. I looked it up in an online database to get the date of production and number produced. While I was doing that I noticed that it lists it as being a 17 jewel movement and mine is a 16 jewel movement with no jewel for the center wheel on the dial side of the movement. The only cap jewels are the balance jewels. Serial numbers match. Any thoughts?