Rolex. A stainless steel keyless wind open face military pocket watch

Rolex. A stainless steel keyless wind open face military pocket watch
Date: Circa 1940
Movement: Nickel finish 15-jewel Swiss lever, cut and compensated bi-metallic balance, No.540
Dial: Black, gilt Arabic numerals, gilt outer minute track with five minute markers, blued steel hands with luminous inserts, subsidiary seconds at 6, No.A.20682
Case: Polished, screw down back, back engraved 'A.20682 G.S.M.K.II'
Signed: Case, dial & movement
Size: 49mm