Well... judging from the engraving on the bell and the size of the horn... I'd say it's a G C Conn euphonium.
Dan Schultz
"The Village Tinker" http://www.thevillagetinker.com" target="_blank
Current 'stable'... Rudolf Meinl 5/4, Marzan (by Willson) euph, King 2341, Alphorn, and other strange stuff.