Well I was thinking that this is now the best candidate I've seen for the model provided to the 1956 Swiss Everest/Lhotse Expedition... the grand-daddy of all Enicar "Sherpas."
We know from Albert Eggler's book on the 1956 Swiss expedition that Enicar supplied "automatic" watches to the Swiss team. Subsequent "Everest expedition" magazine ads for Enicar "Sherpa" watches showed a turtle-lugged watch resembling a Seapearl 600. And I recently discovered a photo of a member of that expediton, confirming that the expedition watches had turtle lugs and black dials. I would expect nothing less than a chronometer-rated movement for such a momentous endeavor. The case-back date of 1-56 is a bit close for an actual expedition watch... the participants left Genoa for Mumbai some time in February of 1956... but the group was
raising funds and donations from industry in December 1955, so it's possible that these special watches were provided brand-new in January-February 1956. Finally, Enicar did not obtain the Sherpa trademark until late 1956, after the expedition, so I wouldn't expect to see "Sherpas" or "Sherpa" on an actual expedition watch.
Here is a photo of 1956 Everest/Lhotse Expedition member Ernst Reiss, with his Enicar:
View attachment 424529
http://www.alpinfo.ch/rueckblick/en/expeditions/bilder56.htmlClick to expand...