I have a very vague memory reading about the 93 Cobra when it came out and something along the lines of Ford digging embles out of the Mustang II Cobra parts bin. I could be way off base on this, but for some reason I think I remember reading that.
All the fender snakes that I have seen have been plastic. The ones in the pics above...those style are plastic. I own my Cobra, and I used to own a 97 Cobra, and a 95 Cobra for a parts. All 3 had plastic emblems.