I turn a lot of Elk and Deer Antler handles for shave brushes and DE razors. The down side to Elk is it is very porous once you get to the center. I seal mine with CA, I would eventually like to build a vacuum chamber to do this instead.
Anyway I use a lot of CA to fill voids with Elk. I would probably think about backing the Elk up with something on the inside of the scales and seal with CA. "IF" the ELK antler would get wet and it's not sealed well, all the dried blood that is caught in the porous part will bleed out, and it's not a pleasant smell. Other then that wet sand, buff, seal, wet sand and buff again