I too have gotten fascinated with some of the older horns but I try to play all of my horns each one, every week. I am trying now to bring about a 1940 martin handcraft imperial, the trumpet is in good shape and plays as good as I can play it. New valves last month. However it needs a main tuning slide stop-rod, and at some point someone removed the bottom valve caps with a wrench and left some damage. Also I don't think the top valve buttons are all original, one has slightly different thread, that said either two are wrong, or one. Hard to tell. Anyone have any sources for these old parts, I have checked with a couple of places and they want to make them new. Even then I am not sure what the originals looked like. The horn is worth the effort, I think it sounds better or at least as good as my committee.