Fwiw, I know ZILCH about "scrimshaw quality" horns but around south TX there are several slaughterhouses & "independent butchers" that will happily sell you cow, ram & goat horns for 2-10.oo each.
(Fwiw, I've made any number of hunting horns from goat/ram horns. - Some sounded GREAT, some "just OK" & some "nearly worthless".)
Note: For those readers, who are within "easy driving distance of" San Antonio, there is a man named Talamanez, who brings horns to the POTEET HWY. FLEA MARKET.
(2 weeks ago, he had 5-6 BIG cardboard boxes full of horns at "sort through & pick" for 3.oo each.)
Otoh, TX Longhorn matching pairs, that are suitable for "wall-mounts" are $$$$$$.
yours, satx