Your best bet is the clean ALL met away from the base of the fan, spread it open, pin the feathers in place, borax it, and after it is dried either super glue or bondo it (you basically fill in where the meat/fat used to be) but make sure it is not too thick to put on your plaque. Its also good to soak the base in white gas for about 1 hour after you flesh it, and before you borax it. This will degrease it and help deter any bugs from ever attacking it.
Of course I have a couple fans from 15 years ago that was just sprinkled with borax and hung up, they still look OK.