Preserving old taxidermy

While I as an animal lover, I am opposed to the hunting of animals for display, I recently inherited some taxidermy mounts from my grandmother. My Step Grandfather went on safari in the 50's and 60's and collected a lot of heads. I now have 3 and I would like to preserve them. They are in decent shape, but are old and not much effort has been put into them. I was wondering what I could do to preserve their coats. I have a comical looking Caribou, whose antler would have painfully grown into his forehead had he not been killed and 2 other African species I have yet to determine the names of. Any ideas about something I could treat them with would be helpful. Thanks, Diane