This was a couple of years ago, but for my 65 I found that the rubber was the same as modern ones and by reusing everything else but the rubber the fit was perfect. I did take the rubber part and matched it up at the parts store.

67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......