I'm sure a taxidermist could give you the proper best way to achieve what your looking for.
That said, I have a lot of pronghorn and a blackbuck euros hanging in my garage. They all looked sort of dry and grey. I saw something online some where so gave it a try... wd40. Gave them a shine and back to black. Totally happy with the results.
But again these are normal animals with very little money invested and totally redneck cure. Lol
Hello! I noticed your E Type in your avatar. What year is it? I have a '69 that looks identical, minus the wire wheels. My car has the steel rims, as I understand it,a more expensive option, but I like the wire wheel much better!