TubeNet

It's my understanding that this is a compensating BBb in the British-Brass-Band style.

I found it on the Miraphone website. On the tubas page, it is the horn at the bottom of the page.

BBb-tuba "Ambassador", compensating, 4 valves


BBb-M9000

- Model Ambassador
- Bell diameter 500 mm (19,685 inch)
- Number of valves 4 (3R/1L)
- 5/4
- 4th valve lock
- waterkey on 1st and 3rd valve slide
- waterkey on tuning slide
- waterkey on 4rd valve slide
- strap ring and lyre holder
- piston valves
- compensating
- Bore of valve section conical 19,6 - 20,4 mm (0,772 - 0,803 inch)
- top action
- protection guard with additional wire
- Material of mouthpipe nickel silver
- Mouthpiece TU33

Yeah, it's been around awhile. Here's a review comparing it, in its prior designation as a 1280, to one of the last Besson 4-valve comps before the Besson bankruptcy:

http://www.4barsrest.com/reviews/products/inst010.asp

did you see who wrote the review?