I have a 70 Western Sport Special Challenger, original paint, SE trim package.
Mine is a bit "gappy" on the right as well,,,not sure if that means anything,,,but it is something i have noticed. Gap is not as noticeable as what you picture on your car.

Biggest problem i have had with the SE trim restoration is finding the clips/hardware to attach the panel...( R/T specialites doesnt have it as well )
Good luck
Doug