Patek Philippe Perpetual Calendar Chronograph
Yellow Gold: Reference 1518
This beautiful Reference 1518 was the first production Perpetual Calendar Chronograph made by Patek Philippe. This beauty incorporates the calibre 13Q''' Chronographe. Patek Philippe began producing the Reference 1518 in 1941 (during World War II) and the last one was produced in 1954.
Patek Philippe only made 281 of the Reference 1518 model, most of which came in yellow and pink gold. There are 47 pink gold examples known to exist today. The example below appears courtesy of Antiquorum. Patek Philippe also made an extremely rare stainless steel version, of which there are 4 known examples in existence today.
Patek Philippe ultimately replaced the Reference 1518 with the Reference 2499 and the Reference 2499/100. The Reference 2499 began production in 1951 and the last example was produced in 1985.
Patek Philippe Perpetual Calendar Chronograph
Stainless Steel: Reference 1518
Alfredo Parmamico is one of the top vintage Patek Philippe collectors (from Italy) and he sent in the photo below of his extremely rare stainless steel Patek Philippe Reference 1518, which is 1 of only 4 known examples. If I recall correctly, Patek Philippe made the stainless steel versions during the World War II years because there was a gold shortage in Switzerland.
It appears in the photo, because of the lighting angle, the moon phase disc might be black, but it's the standard beautiful cobalt-blue color. I know the moon phase disc is cobalt-blue because I have seen other photos of this actual watch.
