If Ted is correct about Zavattero:

Societe Zavattero Feres was founded 1880.

They won a gold medal in 1901.

They participated in an exhibit in Milan, circa 1904 along with:

Chambre de Commerce de Saint-Etienne, Ecole régionale des Arts industriels, Ecole pratique d'Industrie, Manufacture française, Société manufacturière, MM. Gaucher, Darne, Zavattero, Bergeron et Giraudet, Delage, Delhorme, Berthon frères. Les armuriers parisiens : MM. Chobert, Chevalier, Rieger, Lacroix et la Cartoucherie française, sont, comme on le voit, en nombre beaucoup plus petit.

They got patent 367895 on 7 July 1906 for ejectors.

Zavaterro registered 3 makers marks May 10, 1913.

During WWI they were among many who held a contract for the Berthier Carbine. I believe they were many ammunition.

They closed their doors in 1968.

http://wordsdomination.com/darnation.html

Pete