American metal military pocket watch with center seconds Circa 1942

A deck chronometer with lever escapement
–
A military pocket watch deck chronometer with center seconds, made for the British military by Elgin National Watch Co., in Chicago, United States of America, circa 1942. The numbered open faced screwed case was made from metal and has a British military marking. The white enamel dial also has the British military marking, Arabic five minute- and hour numerals, center seconds and blued steel hands. The numbered movement has an Elgin lever escapement in chronometer quality type Raymond, 22 jewels, is adjusted on five positions including temperature and has Geneva striping decoration.
Case dial and movement are signed.
–
Diameter: 51,5 mm
–
Signed: Elgin National Watch Co. S.A. 
–
This Elgin deck watch was used by the British Royal Navy. The engraving H.S. 3 on the back is the British marking for a so called deck watch.