Aircraft Clock, 8-day, Type A-11 AN-5743-1 For parts or repair

This is a mechanical WWII-era aircraft clock, Type 11 AN-5743-1, that was used across nearly all aircraft of the US Air Corps and Air Force, including bombers B-17, B-24, B-25, and fighters P-38, P-40, P-47, and P-51. 

The time is set by pulling out and rotating the knob at the front corner and rotating. However, the winding mechanism is not engaging but may be able to be repaired.  The data label is missing thus the manufacturer is unknown. Measures ~2.25 square and ~1.25 inches deep.