I have been playing the cornetto I made for a little over a year, and I ended up putting some finishing touches on the horn, which made it vastly more playable recently, and I would like to share them for other horn carvers that might like to try. 1) Tone hole size, I ended up making them as big as my fingers can cover. I would recommend doing this first thing it improves the tone centering tremendously. I initially tried to use calculations to get the right tone hole size, if I knew this factor when starting I would do this first, though widening them doesn't necessarily have to change the pitch. 2) Make the throat of the mouth piece quite large. I bought a mouth piece that was tiny, I mean small, it may be traditional, I asked the maker to give it an open throat, but it was still small. I had several others made by a amateur, which he molded after my trumpet pieces, But with the narrow backbore of the traditional one. I ended up re-drilling the trumpet ones with a tapered bit, wallah! I could control the pitch and it sounded tuneful. Quite likely my horn isn't perfect in the lead pipe section, maybe for a refined model a narrow backbore might work OK. 3) Wax the mouthpiece shank. No air leaks!