I'm trying to identify the key of a tuba in the below picture. I suspect it's either a Bb or a Eb but cannot confirm. I tried to measure and it was approx. just over 16ft (although that may be inaccurate). The tuba and the case are of the same brand "Virtuosi". Virtuosi was a British company that's now dissolved which makes it difficult to find information about it.
It has 3 valves, on the valves it has the numbers "0705042" engraved. The diameter of the bell is 16".
I used the wayback machine to try and find more info about the company, but sadly there's a few pictures on the website so I cannot compare images.
The main website: https://web.archive.org/web/20060214044030/http://www.virtuosi.co.uk/
I think a reseller: you can see a EEb and BBb mentioned https://web.archive.org/web/20160808231142/http://www.firstbrass.co.uk/index.php?cPath=1_27_134&
So I tried playing some notes with the Tuner & Metronome App open on Android without pressing any of the valves, without purposely trying to play the lowest note possible the app gave back Bb. B-flat
If I tried to play the lowest note possible it would say Ab.
I assume this means it's an Bb?
Also, to enforce it's a Bb, I mistakenly previously thought that the additional tube in the case was for some optional tuning but realised it's to hold the mouth piece so it faces the other way. So that would add approx. another 1ft to my measurement which would bring it closer to the 18ft for a Bb.