E. Martin Violins

Violins labeled E. Martin, were made in Markneukirchen by Wilhelm Ernst Martin and later by his two sons, Ernst Otto Martin, and Max Alfred Martin. He was assisted by his two sons while he worked and they carried on the business after his death.  From the William Henley, Universal Dictionary of Violin & Bow Makers:

"Martin, Wilhelm Ernst.

Born 1862.  Pupil of E. Glasel.  Worked at Markneukirchen.  Died 1907.  Specialised in making replicas of a Nicolas Lupot model, most of them exported to U.S.A.  Also good Cremonese copies.  Assisted by two sons-Ernst Otto and Max Alfred."

E. Martin violins were originally imported by C. Bruno & Sons company in NY c. 1862 to 1920.  At some point after C. Bruno's death, C.  Bruno & Sons was acquired by Kaman music corporation.  

Bruno & Sons also manufactured instruments, but they are known importers of European Instruments as well.  

Charles Bruno was in partnership with C.F. Martin, founder of Martin guitars, sometime in the 1830's.  It is unclear what their business relationship entailed, but C.F. Martin moved to Nazareth, Pennsylvania in the late 1830's.