As I understood it, no, he could not sell any part of the animal. However, they also mentioned "exceptions" that may be placed into the rules. That might be one of them.
What if you toted the head to Nebraska?
One thing about this proposal, is it doesn't seem even remotely enforcable. But, I don't hear anybody complaining about that (including myself). I don't think anybody could determine that the Elk ivory ring I sold on Ebay came from a non-commercially tagged critter.