Only ones I can find are plastic. My originals are rubber (but not in very good shape), which in my opinion make an actual seal between the housing and fender.
I just took one yesterday, but didn't have time to post until now. The plastic one is from one of the early parts donor cars from many years ago. So, I don't have a clue if it was a 64 or 65. My car is a '65 with an August 28 production date. I have owned it since Feb. 1967.