Those look like 73 - 74 Cuda bumpers. I can see the good chrome left behind where the big "buggy bumpers" were on both the front and rear bumpers, and I don't think they used those in 72. The rear bumper brackets in your pictures also look like the longer "5 MPH bumper" ones used in 73 - 74 to bring the bumpers out away from the body. I'm not sure if they used the heavy inner bumper that you show in 72 either, but I doubt it since that was also part of the "5 MPH bumper" deal. I'm not sure what the brackets are in the bottom picture - maybe something to do with the buggy bumpers? I took the buggy bumpers off my Cuda back in the mid 90's, so I can't remember what all was there.