I use Lincoln's medium brown leather dye. It has much better dyeing properties in it than the more commonly used Feibing's. It also can be manipulated with a wet cloth while still wet, even though it is a spirit stain. I use it on antler, powder horns, and rawhide. It produces a nice dirty patina, that can be applied in layers to get the color, and depth desired. It also can be mixed with Lincoln's other dyes to get the color you desire.
Hungry Horse