Our 1970 grade "A" rear quarter panel extensions have no obvious dings, scrapes, or warping due to over tightening of studs. However, avoiding the bumper contact dents is impossible. These will have small dents from bumper contact. There are very slight differences between 1969 and 1970 and they do carry different part numbers.
Ford part # D0WB-6528518, Mercury MPC # D0WY-6528010-A.
Do you have questions about your Cat's factory pinstriping? This link may help.