Rear bumper guards for 68'dart

They do look a like,

The front has a left and right part number. I believe the difference is that the mounting surface has a taper so it only fit one way.
Whereas the rear can be used left or right. (hopefully they have a part number)

I personally haven't seen a set off the car to know the difference.
Hope that helps. If you have the front as well I would be interested

Thank you