Date: 1942. Owned by Joe Bonasera
The 36I is a double bell euphonium that was made, as far as I know, exclusively for the U.S. Military. It doesn't appear in any of the catalogs I have, so there really isn't all that much I can say about it. It is a 5 valve model, with the fifth valve directing the flow to the large bell or the small bell (on the side operated with the left hand) and the four standard valves being top action.
U.S. Military horns from the 1940's are invariably silver plated, with the serial number engraved on the bell. It seems to me that the 36I is a double bell version of the 84I, which was also being produced for the U.S. Military in the same period.
The bore size on this 36I has been measured to be 0.5625", which is a #5 bore. Although circumstantial evidence suggests that by the 1940's Conn wasn't using a "Wonderphone" and "New Wonder" names anymore for euphoniums (something they had done for longer than other instruments as far as I can tell), this is classified as a "New Wonder". This is because the "Wonderphone" models are always (Large) bell front models, while the "New Wonder" models are always (large) bell up models. Since the 36I appears to be a double bell version of the 84I, I am including the New Wonder name.