Aircraft Clock, USSR, 1940 WWII, Working

This is an fine example of the WWII-era mechanical 8-day Soviet aircraft chronograph clock, 450n. It has a date-stamp on the side of the case indicating a date of manufacture of 1940. Likely made by the 1st Moscow Watch Factory (refer to 0358 at USSRTime.com), but it is not marked as such.

The main large dial is the standard clock display.  Time is set by pulling out and turning the red knob (lower left), then returning it to its center (i.e., home) position on its stem.  The clock is wound by turning this red knob counterclockwise from its home position.

The dial in the upper center displays the elapsed flight time, up to twelve hours.  It is set, stopped, and reset by depressing the spring-loaded red knob from its home position.  Each time it is depressed, the small circular window between its 6 o'clock and center position changes from red (set-on), to red/white (stopped), to white (now reset to zero).

The dial in the lower center is a stopwatch, measuring minutes. It is started by depressing the silver spring-loaded knob (lower right), setting in motion the second hand on the main clock and the minute hand on the stopwatch (both hands are painted deep red and difficult to see in the photos).  An unusual feature is that the minute hand of the stopwatch rotates counterclockwise as it counts the minutes, up to one hour.

Once wound, the clock seems to operate as it should. Measures ~3.25 inches diameter and ~2.5 inches deep.