I believe that there is a very small difference in the very early ones .... 69.5s. I think it is the curve that leads into the thin part of the bumper.
I replaced my front bumper on my 69.5 with one from a 72 and, with it mounted, I didn't notice anything different about it but I didn't put them side by side to compare either
WHAT???? :16suspect I have never seen a difference in the bumpers. I have seen a difference in the early front valences compared to the later ones. It was covered in a thread on here.
Like I said ... you have to be Craig to know this stuff .... it WAS the valance. At least I remember a curved contour on the front of a 69.5 was different, just forgot if it was painted or shiny chrome. Another A+ for Professor Selvey.