I have a similar supply of ancient ivory in various degrees of splits, cracks, and other deterioration. I have been "keeping" it in a large storage plastic clothes storage container near up on a shelf near the heat vent in the basement. When I pick a piece to use, I soak it in some wood stabilizer I get here in MI. It is runny and not a filler, but it seems to do a fair job of locking in the ivory from any futher splits and cracks. I fill the cracks with 2 part epoxy before the stabilizer.
Actually I am soaking ALL organic handle material I use in this stuff now.
Yes, that is one really nice knife shown above.
"The significant problems we face cannot be solved at the same level of thinking we were at when we created them."
At Khe Sanh a sign read "For those who fight for it, life has a flavor the protected never knew".