------------------------------------------------------------------ have links to those tests? ------------------------------------------------------------------ here's one that was done with flutes, a different instrument but the same accoustic principals apply, and this goes even further to show there isn't a large effect by bore *material* iwk.mdw.ac.at/Forschung/english/linortner/linortner_e.htm Personally, I would just play a bunch of horns with different finishes and buy the one you like. That guarantees you get the sound closest to what you are looking for.