Sources of 1926 adverts for the Spartan, to include MyBulova, reflected a dial without sub-seconds and all but two 1927 and other sourced 1928/1929 adverts indicate sub-seconds (see supporting ads). All ads sourced consistently describe the Spartan as “14Kt. white or green gold filled case,” 15 jewel movement, radium dial and having a leather strap. There were a few references to “dust proof case.”
The number "9683" is stamped on the movement; however, I was unsure if this four digit number was a serial number.
The original stamp of the case serial number did not completely strike the first digit; however, after close study, I am confident the first digit is a 6. Additional close-up photographs are available if requested.
This caseback is stamped “14K GOLD FILLED” as opposed to “14K ROLLED GOLD PLATE.”
Signed Bulova: dial, movement, caseback inside.
Unsigned crown measured 6.10mm (digital caliper).
This example seems to wind properly and keep time; however, observation was limited given a complete servicing is pending. The existing hour hand and the remaining portion of the minute hand moves properly in a clockwise and counterclockwise direction and the sub-second hand appears to move properly. The crystal, “dust-proof” cover for the movement and all but the base of the minute hand are absent.
While the bracelet is aftermarket, as a side note, it is marked “STURDY, NICKEL SILVER, PAT 17739688, 1568617.” US Patent 17739688 was filed November 5, 1928 and issued December 17, 1929, Nels T. Nelson, as an individual. Nelson was associated with J.F. Sturdy’s Sons Company of Attleboro Falls, Massachusetts, and had several bracelet related patents observed between at least 1926 and 1933.