The Couturier is actually American! Not only did E.A. Couturier design fully conical instruments, he also avoided sharp turns in the tubing. Yes, you have to spin the horn to empty water! The York is my favorite, unfortunately at high pitch it's near 454 and at low pitch, around 430. It's probably possible to build and extension that would be just right, but I don't know anyone interested in that type of work.