I've seperated two Stebels on two different bikes (one is the Wee). One Stebel has gone over 18,000 miles and the other has about 20,000 miles on it.
I used Tygon 2 fuel line to join the compressor to the trumpet. This hose just press fits inside the trumpet, and onto the compressor, with no extra ties or clamps. There isn't any difference in sound, but I have angled my plastic trumpets downward so that rain and other water will easily flow out of them if it gets inside.
I have photos of my installation if anyone is interested. I was just too lazy to post them yet.