Military Rolex pocket watches were available, circa 1939, in two styles, with either a black luminous or a white non-luminous dial. The black dial pocket watch was evaluated by the British Army and given the grade “General Service Mark II”. The white dial version was not intended for pocket use, and was constructed in a case without a chain bow. This was so that the watch could be inserted in a receptacle within a protective wooden case, or on a vehicle instrument panel. The second pattern was designated by the Army as a “B” type, or “back-up” timepiece to a chronometer watch. The “B” mark used to prefix the issue number of the watch was stamped on the rear of the screw back and on the side of the casing.
The GS Mk.II watch had all the issue numbers prefixed with the letter “A”. The movements of both models are signed by Rolex on the dial case and movement, which is also marked “15 Rubis”. These Rolex movements are actually manufactured as ebauches by the Cortebert watch company, based on Cortebertt’s caliber 526 movement.
