Yes, as I recall Steele made the one I got. It was expensive...I want to say maybe $35 or so? Several years ago I also bought one from a place called ChevyDuty and it was the right molded design. I have no idea who made it, but it worked fine. This would have been in the 80s.
If you have a hard and flat piece of rubber, I can pretty well promise that will be difficult, although the hard flat part might cause it to harbor water a bit less.
