I'd say the one on eBay (Alliance Plastics, Erie PA) has to be a lot later production - compare it to my original I salvaged from my carpet when I changed it in (about)'73-'74 - company was previously Niagara Plastics, Erie, PA, and had the numbers "833" and "3" molded into the reverse side; hope the pictures are clear enough. As was mentioned earlier, it's not rubber, not a hard plastic - kind of in between.
I knew there was a reason why I saved it all these years - just to see how wild prices get on these things sometimes.
This one is in good enough shape to go back in the car. Maybe I could trade it for the Pace Car jacket on eBay - lol.