TubeNet

http://cgi.ebay.com/VERY-NICE-GRAND-SIZ ... dZViewItem

Here I am again with questions to the experts about an ebay horn. (yes money is tight)

This particular tuba is the subject of a thread in another forum here at TubeNet, so I'll avoid going the direction that one is and just ask if anyone is familiar with the make of this one.
Also, how do you "speed up" a sluggish 4th valve?

Got luck with the purchase of an old 1920 Conn with 3 top piston valves a year ago before I knew about TubaNet. Trying to make a good deal for a 4 valve now that I have access to deep thinkers

That 'sluggish 4th valve' could be a lot of things ranging from just dirt and/or mineral deposits to a bad spring to bent linkage... all of which are fairly easy to fix. There is a chance the rotor shaft is bent, the back cap is miss-aligned or the casing has a ding in it.

It's hard to say where the tuba originated or the manufacturer because there isn't much detail in the photos. However, I would venture a guess that the horn is Czech or Russian. That funky brace between the main tuning slide and the bottom branch looks like my Walter Sear-Cerveny (Czech).

Clockspring rotaries are hard to tell; the regularly sprung valves are much simpler to diagnose this part of the world; could just be a bad spring, but only the pros can tell you who could fix it if it is...

Judging that the 4th valve isn't up against the stop, my money's on a bad spring. These old clocksprings can break when they get old. Fortunately, it's a simple repar.