Antiques: Watch rates well for the times

Q My mother purchased this Rolex watch as a gift for my father, who was in the Royal Canadian Air Force in the 1940s. I do not know what she paid for it. The original case says ‘Rolex The World's Most Accurate Wristwatch.’ ‘Oyster Centregraph Shock Resisting Swiss Made’ appears on the 24-hour watch dial face and its crystal has a 2.5-inch diameter (6.4 cm). The watch strap is not original. The serial number is ‘447140.’ The watch is running and keeping time we