I've managed to persuade our band master to let me take home the sovereign that he considers scrap. Apart from a couple of stuck slides and not being able to get the valves out- both easily solvable of course- he says that it goes out of tune above about an F, and reckons that there's something fatally wrong in the valve block. It is also filthy inside of course, but without being able to remove the valves first, I daren't bath it. Does anyone have any advice? I think it's beautiful. Sounds lovely when I play it- and that's on a baritone mouthpiece as I can't find my euphonium one anywhere! Also, can anyone help me on the age of it? It's serial number 582*** Thanks in advance!