Please note that the extract from the archives confirms the case as a Prototype and the white dial was made on special request by the original owner and was made by
Stern Frères now
Stern creations.Reference 3700/1 was equipped with calibre 28-255 C based on a
LeCoultre ebauche, a really thin automatic movement for that time. The cases were manufactured by
Favre-Perret and were 120m waterproofed. The dials were hand made by
Stern Freres. In 1980 Patek Philippe started to create cases and bracelets in their Ateliers Réunis workshops and the Nautilus changed its reference number to the new 3700-11.
For a description of a reference 3700/1 in stainless steel and the caliber 28-255, see: "Patek Philippe Wristwatches" by Martin Huber & Alan Banbery, 1998 edition, pages 230-231.
Please note that both dials were marked with the same stern freres numbers on the back: 93Y * 210TT which means that the black and the white dial are prototype and was made before 1981.