In 1960 Patek Philippe launched their self-winding caliber 27-460. Only 6900 examples were made, with serial numbers 1110000 to 1116899. It became the most successful Patek Philippe self-winding movement. It stemmed from calibre 12-600 which had 30 jewels, whereas the final version of the 27-460 had 37 jewels. The earliest 27-460, like its predecessor had 30 jewels. The present watch, marked ?30 jewels plus 7 jewels?, is, to our knowledge, one of only two bearing this marking to have appeared at auction. The additional seven jewels are the rotor bearings which were previously in steel. It appears that this watch, initially with 30 jewels, was one of the first with a jeweled rotor bearing; thus the addition of ?plus 7 jewels?, making it an important example in the development of the company?s self-winding watches. Another example of the Caliber 27-460 with 37 jewels in yellow gold was sold: Antiquorum, New York, Important Collector's Wristwatches, Pocket Watches & Clocks, December 1, 2004, Lot 188.