How to identify door years?

Not sure about the dart sport but the swinger door had unique regulators in 73 only. The glass was also different because the holes are in a different location. Not sure if this applies to the sport or not.
If you swap them in pairs they should still work I think. I think the door panels are different starting in 73. The 72 back had metal at the top and it switched to plastic trim in 73.