Not sure I know what a Door behind the headlight is?? The headlight buckets are the same I believe. The 73 had a hole pierced in the square plate under the headlight bucket. 73 . The aluminum trim around the outside of headlight is what i call a door. 71 - 72 has a skinny ring.
You are correct in your thoughts David. I am not sure why they are called doors, I would probably call them bezels. I did find them at Ohio Mustangs with Don and they are scheduled to be delivered tomorrow. Thanks for you input David, always appreciated.