With Patek Philippe Extract from the Archives confirming production of the present watch in 1957 and its subsequent sale on 26 February 1958. Furthermore delivered with a copy of Patek Philippe servicing invoice dated 4 August 2006.
Production of reference 2526, Patek Philippe's first self-winding watch, was launched in 1953. The model features the legendary calibre 12-600 AT which was granted Swiss patent No. 289758 in 1953 for "a self-winding mechanism for a wristwatch movement using the energy supplied by a rotary mass causing an eccentric part to transmit a swinging movement to an organ of the mechanism".
Both model and movement are illustrated in Patek Philippe Wristwatches by Martin Huber & Alan Banbery, first edition pp. 168-169, second edition pp. 213, 214, 216-217.