I've been out of circulation for a while, back surgery, which had a good outcome. I'm back from 5 months volunteer work at Puffing Billy. While I was there I lapped in several whistle valve seats. But it occurs to me the #9 whistle in going to sound very much like the whistles on Na's at Puff. I hope it is not as high pitched as the Garratt, (G42) which has, as you might expect, a distinctly British sound....
Linc