Thanks for checking - that is curious... I replaced the side marker lights with OEM type units and they fit no problem. I bring this up b/c I thought they went to the all plastic front side marker in '72. The originals were in such bad shape they wouldn't even hold the bulbs in place. I wonder if there was any difference in the openings?
The only fact I know about the fenders is that the driver side doesn't have the undercoating that was on the rest of the car including the passenger front fender. I've attached photos of the stampings. One difference I noticed is that the passenger side has six "dimples" on the top under the hood while the driver side has five. I don't know if this varied by year or was part of the original design.