With Patek Philippe Extract from the Archives confirming production of the present watch in 1955 and its subsequent sale on October 31, 1955.
To the best of our knowledge the present watch has never before been offered in public.
Patek Philippe produced the reference 2509 from 1950 until approximately 1967. The model is known in three series:
1st series, caliber 12-120
2nd series, caliber 12-400
3rd series, caliber 27AM 400
A similar model is illustrated in Patek Philippe Wristwatches, by O. Patrizzi, Volume 2, p. 170, pl. 727.