ROLEX Ref. 6239/6238

ROLEX REF. 6239 COSMOGRAPH DAYTONA UNDERLINE DIAL STEEL Rolex Cosmograph, Daytona, case No.923332, Ref. 6239/6238. Made circa 1963. Very fine and unusual, water-resistant, stainless steel wristwatch with round button chronograph, registers, tachometer, steel bezel graduated to 300 UPH. Three-body, polished and brushed, screw-down case back and crown, tachometer on the bezel graduated to 300 units per hour, inner case stamped with Ref. 6238. Bi-color black and silver with applied faceted steel baton indexes and luminous dots, outer 1/5th seconds track, subsidiary silver guilloche dials for the seconds, the 12-hour and 30-minute registers, silver pint underline beneath Cosmograph. Luminous steel baton hands. Cal. 72B, rhodium-plated, 17 jewels, straight-line lever escapement, monometallic balance, shock absorber, self-compensating free-sprung Breguet balance spring, Microstella regulating screws. Notes Case, dial and movement signed. DIAM. 37 mm. THICKNESS 13 mm. Launched in 1963, this example of ROLEX COSMOGRAPH DAYTONA represents one of the earliest made, as is evident from the serial number and REF. 6238 (pre-Daytona) case back. The watch is further enhanced by a strong case retaining good THICKNESS to the shoulders, 300 unit bezel, well-preserved and attractively aged luminous dots and rare underline dial.