Rare Patek Philippe 18K pink gold ref. 2511, made and sold in 1955. As one of the largest and rarest of the 1950s Calatrava models, ref. 2511 is not a watch many people have seen before outside of the Patek Philippe Museum in Geneva. This reference was only made for a short period from 1951-1955. There are only six examples of the reference previously known to exist in 18K yellow gold, and only 5 in rose gold. The massive 36.5 mm case of this watch has a signature “empire” style with fluted lugs and fluted sides. Note the parallel molded design around the case and matching pattern on the lugs. The case was made by Dubois & Cie in Le Locle and the dial was made by Stern Frères. As one of the rarest and largest mid-century Calatrava watches, this is a wearable work of art that deserves a new home in an important vintage Patek Philippe collection. This example is exceptionally preserved and based on our research, the last example of the reference to leave the factory.