Rolex Ref 6263 Daytona, Sigma Dial, Circa 1975, Full Set, Very Nice

Swiss T” signature at 6 o’clock. The Sigma dial was a feature of luxury Swiss watches in the first half of 1970s when the guidelines by the Swiss watch industry association APRIOR suggested that dials bearing gold markers and hands be stamped with the Sigma notation to distinguish them from base metals. Since this was only a suggestion (rather than a rule) and the notation was rarely understood by customers or dealers at the time, the convention was used sparingly. Sigma dials were eventually abandoned around the middle of the decade. Nevertheless, on Rolex steel sport watches the rarity of the Sigma dial also serves to authenticate the age and the originality of the dial, because there were no service sigma dials issued after the 70s. This Ref 6263 Daytona is in great condition with full proportions to the case and sharp lugs.  The case was carefully taken care of and was not subject to excessive polishing. The model/serial numbers between the lugs are clear and unpolished. The dial i