Yes Conn (aka Conn-Selmer) is still here but I do not know about the museum. Lake Maxinkuckee is a great place for Walleye!
Ah, yes. Conn makes some nice trombones.
Those trombones I believe could be Bach trombones. I am a Design Engineer at Conn-Selmer’s woodwind plant. I mostly design flutes, piccolo’s, clarinets, etc.