Bear in mind that these animals are not targets for trophy hunters, most of the time - in Africa, rhinoceros are the single most protected animal of all! In South Africa, several dozen a year are killed because they've gone rogue and must be shot to protect people and/or other animals, or are injured by predators and put down by rangers to end their suffering, or for some other good reason. They are fully utilized for the benefit of game conservation and local tribespeople. The skin is tanned into leather, and can be obtained in finished products or as leather if you are prepared to pay for shipping the stuff to the USA. I've brought some back with me as gifts before now. The same applies to elephant, buffalo, hippo, etc.
Skunk, if you really want some of this stuff, PM me and I'll see what I can find out from my contacts back in South Africa. I don't think there's any legal problem in bringing the stuff in, but you'll have to pay for shipping.