Tip for black horn, use a scribe to scratch the outline into the horn rather than use a pencil. Much easier to see.
I do have the advantage of a 2x72 belt grinder but I don’t spend long on it at all. Just sanding the outline to shape and beveling the edges. After that I use files and hand scrapers to do all the shaping before going over everything with 220 grit paper then 400 grit. Next it’s onto a Chemcote yellow stitched buff with Tripoli compound then a loose cotton wheel with fine rouge to finish to a high gloss.
I like the scribe idea and will definitely try it on my next outing. Would be fun, but I am having trouble seeing a 2 x 72 in my future. I think a lot of it is just confidence. I am still very cautious about not wanting to remove too much material.