This 1890 Seth Thomas convertible 18-size Model 4 pocket watch was manufactured with a gilt finished 3/4 plate, 7 jewels, and it is non-adjusted. The movement is key wound and key set, with a flat hair spring, and plain/simple regulator. Its serial number is 35062, and its grade is Seth Thomas numbered grade 11.  The movement is signed “Seth Thomas Thomaston, Conn.”.  This is the 62nd Seth Thomas Model 4 pocket watch produced. Model 4 serial numbers started at 35001 and concluded at 718400. 

Model 4 movements were made with only 1 casing screw, at the VI o’clock position, to hold the movement in the case; but there is also a small brass pin protruding from the side of the perimeter of the movement, at the XI o’clock position, which matches a notch on the inside of the special open-face watch cases made for key wound movements.  Inserting the brass pin into this notch helps to stabilize the movement in the open-face orientation in the case.  There is also a special notch in the special hunting watch case, at two o’clock position, to help stabilize the movement in the hunting case orientation.  Because there is no winding stem orientation to consider Model 4 is adaptable to either open-face or hunting case orientation. The placement of the winding hole in the open-face and hunting case dust covers can be compared in the side-by-side photos below.