1972 doors have their own window regulator.
All 72-77 doors have the door lock button thru the metal.
78-80 doors use the plastic grommet around the door lock button.
72-74 doors will only accept the screws on SMC door panels and the sheetmetal door panels.
In 1975 the plastic clipped on door panels were introduced.
In 1976 the door handle recess was introduced.
Early doors had a bolt in window regulator. Later doors used rivets.
1975 doors are unique. The only year to use plastic clip on panels but no door handle recess.
1978-80 door use the push button vent window lock.

As a quick spotters guide:
72-74 doors are mostly the same but will only take screw on door panels
1975 doors will take any door panel and have no button grommet and no door handle recess
1976-77 doors have the recess and flip up vent lock, no lock button grommet.
78-80 doors have the recess, push button vent lock and lock button grommet.

Fenders have many variations too but all years will physically fit.
( antenna holes, and holes for items on the inner being the main differences