This may be the longest clip I've seen on American TV shows. It's from Our Miss Brooks, a 50's sitcom. The instrument is more of the German-style baritone/tenorhorn, but they called it a peckhorn. Must have been on a dusty shelf in the prop room, because I seriously doubt ANY public school in the U.S. in the 1950's would have had those instruments. I chopped out all the scenes that did not show the horn in the video linked below.
Anyway, even though we never really get to hear it played, it's cool looking!
https://www.youtube.com/watch?v=j-pzf_u4kbY
Here is a screen shot: