'73 Duster rear bumper

New guy here. I just picked up my 73 Duster on Saturday and as I was taking off the rear bumper guards today I saw that the bumper is mounted to brackets and the bumper is pulled up fairly close to the body. But, the more I look at the bumper the more I realize it's really not salvageable and the local chrome shops are wanting over $500 so I started looking for repos and that's when I see there are no 73 bumpers available anywhere. Assuming the rear bumper didn't change, just the way it was mounted, I suppose I can use a 72 bumper. Help me if I'm wrong please.