To the best of our knowledge the present watch has never before been offered in public.
The references 3548 and 3546 were the first Ellipse models produced. Launched in 1967, Patek Philippe manufactured this reference until 1978 when the model was replaced by the reference 3748. Currently the only Ellipse model made by Patek Philippe is the reference 3737.
A similar model is illustrated in Patek Philippe Wristwatches, by O. Patrizzi, Volume 2, p. 235, plate 979.