I'm impressed. It's my understanding horn is a difficult medium. Well done.
I got rams horns from a local vet who makes shepherd's crooks. What I got were his offcuts, so the first difficulty was finding enough material to cut into blanks. When I first got them I boiled one for 20 minutes and then straightened it on a vice before turning it. A couple of months the pen had a couple of cracks. I should have left it for a while before turning.
The horns have now been sitting in the workshop for 2 years and I was able to cut the blanks on a bandsaw.
Turning is not easy because of the hardness and shape of the horn, but is ok to turn when round.
Alan