One thing I've learned from this discussion is that the 73 rear bumper "cushions" (there's the right word) seem to be very common for one-year only as opposed to the smaller/shorter cushions made for three years (70-72). I have five or more used OEM rear bumpers that I've purchased at swap meets and on CL. Most of those had at least one 73 cushion and none of those bumpers are 73. Yet some of them had the shorter bumper brackets and some had the longer brackets that I understood to be for 73. I only have one bumper that has just one of the 70-72 bumper cushions. I guess that illustrates with some of these 40+ year-old parts, you can end up with a one-year only bracket that would not be correct on a three-year produced bumper with an incorrect one-year only cushion. Damn.