Important Collectors' Wristwatches, Pocket Watches & Clocks LOT 325 Rolex Ref. 6263 Oyster Cosmograph Daytona Rolex, Genève, case No. 5382646, Ref. 6263 / 6239. Made circa 1977. Fine, water-resistant, stainless steel wrist-watch with black bezel, round button chro-nograph, registers, tachometer and a stainless steel Rolex Oyster bracelet Ref. 78350. Accompanied by a fitted box, blank guarantee certificate (now void), hang tag, booklets and polishing cloth. C. Three-body, polished and brushed, screweddown case back, buttons and Triplock winding crown, tachometer graduation on the bezel to 200 units per hour. D. Bicolor black and silver with applied steel baton indexes and luminous dots, outer 1/5th seconds track, subsidiary guilloché dials for the seconds, the 12-hour and 30-minute registers. Luminous steel baton hands. M. Cal. 727, rhodium-plated, 17 jewels, straight-line lever escapement, monometallic balance adjusted to 3 positions, shock absorber, self-compensating Breguet balance spring, Microstella regulating screws. Dial, case and movement signed. Diam. 37 mm. Thickness 13 mm. Approx. overall length 200 mm. Estimate: 25,000 USD - 30,000 USD Estimate: 20,000 EUR - 25,000 EUR Estimate: 28,000 CHF - 35,000 CHF Grading system C 3-8 D 3-6-01 M 3* AAA Click here for written condition report See high definition image The term Sigma dial refers to the addition of the O symbol flanking the T Swiss T signature at the bottom of the dial that resembles the letter Sigma in the Greek alphabet. The "O" on the Rolex dials refers to the Italian word "Oro", or the French "Or", and indicates the use of white gold batons. Sigma dials, particularly with the famous "Big Red" Daytona signature, are considered the most desirable dial after the Paul Newman version. Important Collectors' Wristwatches, Pocket Watches & Clocks 10-06-2010 Sold including buyer's premium: 28,800 USD