First some background:
I've been playing euphonium for the past 8 years, but never owned my own horn. Since I graduated high school a few months ago, I've been stuck playing a plastic trombone and York cornet from the 50s. I intend to play euphonium in college, though I'm not majoring in music. I do, however, plan on playing for the rest of my life. I played on a Yamaha YEP321 for the past 4 years.
I'm currently in a situation where I'm deciding between a restored 1905 Boosey 3+1 compensator and a Mack Brass compensator. The Boosey has been restored with replated valves, and I intend to try it out in the near future. Are there any specific things to think about trying such an old horn? No matter which of these two horns I purchase, I'll have to buy a new mouthpiece, since one is large shank and the other is euro shank. I've only ever played on small shank. I've seen so many good reviews of the Mack brass euphonium, but I also like the potential resale value of a Boosey instrument (which I may not get with a Chinese clone) Any thoughts?