years back, I replaced my non-functioning '36 mechanism w/a mechanism from a '46/'47 lonnnng trumpet horn duo. The '46/47 mechanism is exactly the same as the '36 mechanism. (who woulda thunk! I bought the '46/'47 horn duo online for under ten bucks plus the shipping; so nothin' ta lose. Upon receiving the '46/'47 duo I realized that each-horn-mechanism was identical to the '36 mechanism.