Ancient Eastern European Contrabass Helicons

[bigtubby]

Fully aware that this is the knee jerk TubeNet reaction to any unknown tuba of European origin: I think that this is probably a very old Cerveny.
http://youtu.be/MAarxcIAjzk

[bigtubby]

After looking more carefully I would like to retract my "probably an old Cerveny" assessment. One of the reasons that "Cerveny" is a knee jerk reaction is the fact that so many European tubas were copied of or at least inspired by V. F. Cerveny's designs. My above assessment was based on a memory of an image from an old Cerveny catalog:


Which is quite similar (except 3V vs 4V; keel in wrong place). Then I found a photo of Gideon with this helicon:


... and I see that it has the "pin" style stop arms like my 1890-ish Schuster Army model tuba. I've never seen a Cerveny tuba (or a photo of one) with that type of stop arm. The old Cervenys I've seen have the stop arm that interacts with the S link and has no stop mechanism on the top plate of the valve housing:


Of course the fact that I've never seen one doesn't mean that they don't exist. Input?