Understanding that this response is a bit late, but better to be late than never, here is my suggestion: after you have polished the horn to your desired level of luster, apply a thin coating of aqua fortis and using a propane or oxy/acetylene torch gently heat the horn until yellow begins to show. Applying more heat will deepen the color but beware not to burn the horn. That can happen fast! Aqua fortis gives the horn an aged and well used patina. Additional coats of aqua fortis and heat may be repeated, if required.
Aqua fortis, I believe, can be purchased from Track of The Wolf or you can make it yourself by dissolving iron filing in nitric acid.
After the desired color has been achieved, coat the horn with cedar oil to keep the horn worms away. Once or twice a year is satisfactory. The oil also keeps the horn supple.
Renquist Knotcradle, a pied poudreux of a major kind.
