Rolex Datejust "Sigma"

Two Greek sigmas flank the T SWISS T line at six o'clock on this silver dial, and that small marking is exactly what collectors look for. It came out of the Swiss APIOR gold-promotion campaign, first used in February 1970, and it certifies that the hour markers, and usually the hands as well, are solid gold rather than plated. Rolex used the sigma marking on dials through much of the 1970s. Reference 1603 is the steel vintage Rolex Datejust defined by its engine-turned bezel, the middle path between the smooth-bezel 1600 and the fluted 1601.

The dial here is plain silver with applied baton indices and matching hands, and the date sits at three beneath the cyclops. The 36 mm steel case holds a self-winding caliber of the 1570 family, a chronometer running at 19,800 vph with roughly 48 hours of reserve. The date advances by running the hands around the dial, since quickset arrived only with the later generation. Acrylic crystal, screw-down crown and Jubilee bracelet are all period-correct, the bracelet closing on a brushed and polished steel folding clasp. It comes as a full set with its box and papers.

The luminous material on the hands and at the index tips has yellowed slightly and evenly, which is the aging collectors want to see on a dial of this age. The acrylic crystal shows light surface marks and hairlines. Fine hairlines run along the case flanks and bracelet links, and the grooves of the engine-turned bezel have softened a little with wear.

The watch is presented on its Jubilee bracelet with the steel folding clasp.