Rolex: A late 1940's steel Oyster chronograph anti-magnetique triple calendar wristwatch with outer-date ring and central date hand, raised square gilt hour marks, Arabic five minute divisions, subsidiary dials for running seconds, elapsed minutes and hours, apertures for day and month, sweep centre seconds operated by two round buttons in the band, the case with screw-down winder and screwed back with makers mark and No. 4767, the signed movement jewelled to the centre with 17 jewels adjusted to 3 positions and numbered under the yellow metal balance 730R, with steel bracelet and deployant clasp