I was actually able to do a render with the fins on another head but its not as realistic looking as your golden age cowl.That thing is just awesome, Its one of my favorite pieces in my entire runtime.

http://www.renderosity.com/mod/gallery/index.php?image_id=2356363&user_id=424381&np&np

Ya know, is there a way to hide the cape on the golden age cowl.