These little clocks were ubiquitous in Army and Marine aircraft, and also post-war planes.

Because so many tens of thousands of these had to be made, at least half a dozen companies cranked them out: Bulova, Wakmann, Elgin, Waltham Watch Co., Longines-Wittnauer Clock Co., and so on.

Normally, the manufacturer would have its name printed clearly under the "8 DAYS," but not in this case.  So I don't know which company made this particular A-11.

Nevertheless, it still keeps pretty good time, about five minutes slow every week.  Since one has to wind it up weekly anyway, it's not a big deal to synchronize at the same time. 

This particular clock is special — my Pacific Theater-serving brother, Louis, rowed out at low tide one day in 1944 and unscrewed it from the control panel of a P-38 fighter that had crashed just off the coast of Guam. 

(photo from the gallery of Jan Kocian)