This model, reference 2526, was launched in 1953. It is thought that only 580 examples were made, the majority of which are in yellow gold, and only very few in pink gold.
The present lot is exceedingly unusual as it includes the Certificate of Origin, original bill of receipt dated June 26th, 1956 and the Patek Philippe strap and spring bars that it was sold with. It appears that the strap has never been placed on the watch.
Other examples of this model are illustrated in Patek Philippe Wristwatches by Martin Huber & Alan Banbery, 1st edition pp. 168-169, 2nd edition pp. 213, 216-217.