What are these holes for above tail lights?

Being a metal worker by trade...I believe those holes are "die holes" used to align the sheet material (with pins, or dowels in the die) when the stamping occurs. The flat material is an exact shape prior to stamping (or pressing) allowing the manufacturer to use a minimum of material and not require trimming. The die holes insure that the flat pattern is located in the stamper properly. I could be wrong, as I'm not real familiar with the 70's Duster's body in a disassembled condition.