A friend of mine recently sent me images of a small brochure that Conn produced in 1926 that is devoted to the big horns. Here's the cover:
Not surprisingly, when it talks about Sousaphones, Conn once again boasts - wrongly - of having created the very first one:
While that page gets it wrong, another page provides a fascinating list of tuba players - past and present - that played Conn basses at one time in their career.
While he had passed away six years earlier, Herman Conrad, the very first Sousaphonist, made the list (which is alphabetized, if you didn't catch that). But he is listed as playing in the "Victor Talking Machine Band, New York City."
Conrad was with Victor from 1903, when he left the Sousa Band, until he died in 1920. But to my knowledge, he always worked with Victor in Camden, NJ, and lived in Philadelphia.