I found the nelow history lifted from the web, it was with a listing for a very old Heuer Moonphase..
It suggests that E. Gübelin was the mark of their jewelers arm of the business.

"Gübelin, E of Lucerne. In the 1854 Jacques Edouard Gübelin married the daughter of the watchmaker Maurice Breitschmid. He joined Maurice in his business in Lucerne. 1905 saw them acquire a building called "Palais Anglais" at 1 Schweizerhofquai. this was still the headquarters in 1989. The 1915 and 1920 listings show the company as Ed. Gübelin. By 1919, Edouard, son of Jacques Edouard was head of the firm and opened a New York outlet. This outlet was for watches but by 1921 also sold jewelry.

The company used watches made by many prominent makers such as Audemars Piguet, Haas, Neveux, Niton, Patek Philippe and Vacheron Constantin. In 1925 and 1928 the company listed had changed to Ed Gübelin under watches and E. Gübelin under jewellers. In 1940 Gübelin exhibited at the 1940 New York World's Fair under the name E. Gübelin, located in Lucerne and Zurich. The goods were imported into the USA by E. Gübelin Inc. of New York.
Around 1949 the name of the form changed to Gübelin Fils. and in 1957 was listed as Les Fils Gübelin.By 1966 this had changed to Gübelin AG and Gübelin Söhne. In 1973 at Basle they exhibited as Gübelin SA.

The company has continued through 5 generations of the family and was still trading in 1990. From about 1982 to about 1985, the designer Richard Daners worked with Walter Gübelin and his son Thomas to produce some one off masterpiece watches."

Link here: http://www.goodtech.biz/watch/images-heuer/heuer-03/ebay.htm

Cheers
Stewart