Model 2  - 21 Jewel Movement S.N.2621350 from 1938 - 16 Size Case, Glass Crystal -

Base Medal Case with Matching Numbers 1070338 Inner Case and Case-Back and also

it does Not Have Military Contract Numbers Inscribed... It was a Design Concept Only !!!

Note: Only Example with a Black Montgomery Dial & Silver-Numerals !!!  I Purchased 

this Rare Timepiece from a Former Hamilton Watch Design Department Employee !!! 

The other more known version is the Bu, Aero. G.C.T. Black Dial with Military Markings !!!