Bondo works great if you prep both surfaces well. Make sure all cartridge is removed from inside the sheaths. Clean with dawn soap and hot water, let air dry. Use a bit of lysol if smell is still there. Next clean horns and inside of sheaths with lacquer thinner. Let dry, drill a few holes threw horn bone not the sheath. This will allow the bondo to grab onto the bone. I like to use the bondo number 2 it has bits of fiberglass strands in it. But Reg bondo with chopped fiber will work also. Just put a small coat on bone then some on the inside of the sheaths then slide them over the bone at the same time. You need to do both at the same time to make sure you get them back to the original position that they were. Hight and width wise.