AIrcraft Clock, 8-Day, AN-5743-T-1A

This is a Cold-War-era 8-Day Aircraft Clock AN-5743-T-1A made for aircraft manufactured by Douglas Aircraft Corporation, as evidenced by the order number prefix "DA". The serial number prefix of "51" is indicative of a manufacturing order dated 1951.  May have been used in the Douglas Skyraider attack aircraft. 

The adjustment/winding knob pulls out and adjusts the time, however, the clock only runs for several seconds. It likely needs servicing by a qualified watchmaker. Otherwise, it is in very good condition. Measures 2 3/8 in square and 1.5 in deep.