Dave,
Just a thought here....if you've not worked with "fresh" ivory a lot, it can be a real headache. I quit using it a number of years ago when I spent the better part of a month working on a bowie where the customer wanted elephant ivory.
I finished the knife, laid it on the leather working bench (which just happened to have a window over it with the sun shining through, and onto the knife.) I went into the house to get a glass of tea, came back about 15 mins later and the entire handle was split....not checked, not cracked, but split from one end to the other with about 1/8" split. I had heard from other makers of this happening to them, but always thought they were nuts....until it happened to me. The ivory was warm to the touch from the sun shining on it, but not "hot". Just an example of how "quirky" fresh ivory can be.
That episode cost me a $300 chunk of ivory, a customer who was ticked that his knife wasn't done on schedule, plus the time and frustration of having to tear the knife apart and basically rebuild the guard, handle, and butt cap, plus the cost of more ivory. I simply refuse to use the material any more, and although it will cost the customer more, fossil ivory is the only type I will use if a customer specifies "Ivory". Even the fossil ivories have quirks, but they are far fewer, and far less severe than "fresh" ivory.