I have a Viceroy C whistle, found at a garage sale, with a very sweet sound, but it is a penny whistle. There is no thumb hole in the back of the whistle on mine. Yours sounds almost like a recorder - do you like the sound you're able to get out of it? It could give you the flexibility of a whistle with the range of notes of a recorder with its ability to do # and flats.

Colleen