This is a photo taken from the inside cover of "Henry Silberhorn's Instructor for the Concertina" book fifth edition. The first edition of this instruction book was published in 1910. The sixth edition was published in 1927. This picture was most likely taken in the early 1920's. It's also interesting to note that he's holding a concertina that has more than the usual number of buttons. This one looks similiar to a bandoneon.
The fifth edition instruction book was sold by the Georgi and Vitak Music
Company while the sixth edition was sold by the Vitak-Elsnic Company.
This would indicate that the Vitak-Elsnic Company was formed in about 1926.
The owners of the Georgi and Vitak Music company's names were Otto Georgi and
Louis Vitak. Mr. Elsnic's first name was Joseph.