How to identify door years?

Oh I don't think I'm an expert, I've just seen a few of these things.

Here's a picture of the door impact beam, looks like '73's didn't get them (or at least not all of them). There's a little more information in this thread, although not all of it is correct. '74 is not a one year only door like suggested in this other thread

73 to 72 Dodge Dart door swap

img_1746-jpeg.jpg

I'll see if I have a picture of the lift mechanism somewhere