...and I agree with Gavin in the regard that most CITES enforcers aren't too sharp at worked materials ID and in my experience 99% of customs officers couldn't tie their shoelaces without a flowchart.
Then again, very rarely you have nerd-flies - like me - and we will pounce on your ivory like flies on... well a Yataghan!
IMO, Gav said it: Why chance it.
Peace, - Thor