Vacheron Constantin confirm production of the present watch in 1936. It was made for the German Airforce and is most probably part of an extremely small series of aviator's watches manufactured during this period.
The present watch is fitted with a "Gradmass" dial graduated for 60 and 360 degrees. The second hand makes a complete revolution in 4 minutes while the minute hand progresses of 1 degree (equal to 240 seconds). The minute hand takes four hours to revolve while the hour hand moves forward of 60 degrees, performing a complete revolution in 24 hours for 360 degrees.
A similar model bearing case number 260918 as well as the model numbered 260920 featuring the additional complication of a split seconds chronograph are illustrated in The World of Vacheron Constantin by C.Lambelet/L. Coen, p. 403.
The case of the present watch is in addition to its number 260919 engraved with the number 2, probably indicating that it is the second example of this particular model made. The fact that number 260920 is a single button split seconds aviator's watch supports the idea that no more than two examples of the present model were ever manufactured.