With Patek Philippe Extract from the Archives confirming production of the present watch with silvered dial and raised hour markers in steel in 1944 and its subsequent sale on 31 January 1945.
This watch is thought to be one of only thirteen examples of this reference in stainless steel known to date, all dial versions combined.
Reference number 530 was usually reserved for the renowned oversized chronograph wristwatch, introduced into the market in 1938. However, research resulted in the discovery of the fact that reference 530 was used not just for the chronograph but also for a plain model without any complications. Whereas the present watch very much resembles a traditional reference 570, close examination shows differences in case proportions such as a larger diameter of 36.5 mm. and a substantial bracelet width of 22.5 mm.