Wagon doors are wagon ONLY. Any year sedan door will fit a 73 but 74-up doors need the 74-up upper hinge. The lower is the same but the upper hinge on early doors has less distance between the 2 bolts.

The reason the wagon doors won't fit is because the window frame is different. On the wagon the back end of the window frame runs straighter to to follow the roof line where as on the sedan it curves downward. It MIGHT be that in a pinch a sedan door would possibly fit a wagon, but if it even did there would be a gap in the rearward corner where the sedan door curves downward.