TubeNet

That looks almost identical to a BBb miraphone I played one summer in a community band north of Los Angeles. The horn I played had a detachable bell and two cases. I believe the bell case was octagonal or hexagonal and opened from the top.

It played very nicely and centered amazingly well. The linkage was a little noisy, but all the tolerances were right and it had no leaks.

It would not surprise me if this was the same exact horn. I believe it belonged to a middle school and was in storage before they pulled it out for me to play a summer season with the community band. If it is... That would be a wonderful horn to restore and would make its owner very happy.

A very large percentage of the detachable bell Miraphones (if not all) came with recording bells. The pitch goes up when the bell is changed to an upright bell.... accounting for the long tuning slide. It's my opinion that Miraphone used two different crooks immediately following the main tuning slide to compensate for this. ... a shorter one for recording bells.