TubeNet

Very cool horn!

http://www.ebay.com/itm/VERY-RARE-Vinta ... SwUV9WpqeD" target="_blank

https://www.youtube.com/watch?v=xzGjwGY-lh8" target="_blank

There was a lot of junk with similar bell circle, commonly under the name "mellophone." Top valves in a trumpet-like configuration, where this has side valves and receiver on the bell, seems to me like the main difference. The bore on this one could be larger, I think classic mellophone shank is closer to trumpet.

This is an example of a soprano (Eb) helicon--a round, circular or 'butterfly' cornet of the helicon family:



This is an example of an alto Eb helicon:

Wow - the varieties and designs of musical instruments are astounding. These pieces are a work of art.