Dealership Step Bumper Question

[cericd]

I'm thinking about reaching out to salvage yards in the town where my truck was originally purchased to look for a rear step bumper with the dealership name stamped into it and I'm wondering if it will have to come off a 67-72 or would a 60-66 or 73-87 fit properly. I'm not sure if the width of the cutout beneath the tailgate would be the same or if the brackets would line up with my 1970 frame.

Anyone know for sure?