The rear bumper is from a 70 through 72 Cadillac with the small back up lights. As Brian said, Good Luck finding them. Last year I purchased two from Jeremy that I was going to use on my Lifeliner but ended up using the right side on the Criterion. I still have the left side and hope to get another right and replace them on the Lifeliner.
Last I heard Attila had a set for sale. Might want to check with him.