Use borax. First, remove as much meat and fat from the base of the tail, paying attention any fat around the base of the feathers.
Pin the fan in the orientation you want on some cardboard (or whatever) and cover the base of the tail with borax. After 1-2 weeks, knock off the "old" borax, and recover the skin, making sure to rub fresh borax into the base of the tail.
Salt is hygroscopic, meaning it will attract and retain moisture. If you want to keep the tail, borax will preserve it longer, in better shape than salt.