You don't have to do anything to the legs after they are dried out. They'll last for years! I take a little finish nail and nail them to the back of the plaques so that the legs and spurs hang down beside the beard. Makes for a good looking mount.
On the fan base, you need to get as much of that yellow fat out as you can. Then, use Borax on the fan base to dry out the remaining fat and preserve the base. Make sure you spread the fan out before applying the Borax. Once it dries out it's pretty well fixed in position.
A turkey fan mount is something just about anyone can do with a little time.