With Patek Philippe sales tag and Extract from the Archives confirming production of the present watch in 1943 and its subsequent sale on 9 November 1943.
Reference 591 differs from all other Patek Philippe chronographs by its generous yet subtle case proportions. Its cylindrical body highlighted by a stepped bezel is crowned with four "bean-shaped" lugs with straight sides. Consequently, this reference responds particularly badly to insensible polishing as it quickly loses the angle to the bezel and the edges to the lugs.
This example however is very attractive and one can fully appreciate the savoir-faire of Patek Philippe's designers in the late 30s when this model was introduced to the market. Furthermore, the dial of the present reference 591 is blessed with the sought-after Breguet numerals and results in an overall very appealing look.
Reference 591 is illustrated in Patek Philippe Wristwatches by Martin Huber and Alan Banbery, second edition, p. 266, pl. 411.