A very interesting segmentation Johnny, with a very nice general appearance.
For my taste, the bone rings could be more regularly wide. And maybe the shape could be more flowing (the centre of the barrel looks flat) and the horn doesn't seem that flush with metal parts, but the pics are often misleading.
Btw, I got a horn blank some time ago, yet unturned. It has some white marks in it, it seems that yours have it too. Is it easy to turn and polish?