By the way, I think your photos present the horns pretty well.
That said, I have experimented with photographing horns a little. I think the tricky part is too much light reflecting off of high spots. Horns seem by nature to have surfaces that will shine. What worked for me was using a tripod for the digital camera, allowing a longer exposure time. Then, instead of putting the photo lamps on the subject, I aim them at the ceiling and let the light bounce back down. Seems to work pretty well so that the details don't get washed out. Just a thought.
Best wishes, Marc