With the undyed horn body, and nontraditional base, I’d place it in the 1980s. A lot of horns from that era were not dyed. My initials are BH, but it’s not one of mine. 😀.
It’s well done for that period. Probably not someone who just made a couple of them, although it could have been scrimmed by a separate hand other than the horn maker. I would inquire with Bruce Horn. But if she is from the west, there were a few guys in that neck of the woods making them. Even F & I horns, once some of the early books were published. So I wouldn’t rule west of the Mississippi out.