You may also want to consider a European mount since you live in Europe. If you are hunting with relatives or friends you may be able to have it boiled and done and carry it back with you. (call the airline, a skull would certainly be an interesting carry on piece) Keep in mind that these skull mounts are getting more and more popular here in the new world.

If you could not carry it on, it would be light weight if you box it up, any surcharge would not be too stiff. It could even be part of your allowed luggage if you travel light.

Bob

(Check what is allowed through customs first though. I would think that would not be a problem.)