I too had some issues with amd outers on a 69 plylmouth. The Rt side is correct and matches the contours of the factory inner wheelhouse especially where it meets the inner wheelhouse flange in front of the roof/sail support. It fits really nice, almost perfect even the holes. However the problem with the Lt outer is that it appears to be missing part of the flange where it attaches to the inner in front of the roof/sail support. The flange isn't "tall" enough to attach the wheelhouse's and interior support together. Also the Rt wheel house at the rear lower has a small extension piece toward the center-line of the car. The Lt doesn't.
After mock up and initial fit I modified the lt outer hoping to solve the issue and noticed that the wheel house was incorrect. So I ordered another one from the same vendor and the second was the same. I then contacted amd direct instead of the vendor. I'm not sure if this is a poor reproduction or miss packaging error. I'm aware that these are "aftermarket" parts and that fit and finish are not a guarantee but this is a bit drastic in my opinion. They did pull one in there inventory and looked the same but the response I got was not what I had expected. Basically telling my to modify the wheel house and make it fit. What pissed me off the most is the fact that the passenger was perfect.
Driver side is the top photo.