There's been a ton of door handle related posts and quite often, there's been mention of the "Chevelle bend" as it relates to the button rod. The button on the passenger door on my '70 Elky works, but has to be pushed in to the max in order to open the door. Does it sound like the fix is as simple as re-bending the rod? Latch and striker adjustment seems to be ok.

It might be that simple, but more likely whoever put the handle on cut the rod too short. The repro door handles come with a long rod sticking out of the pushbutton, that you have to cut to fit your application. You might roll the window all the way down, take a flashlight and look towards the back of the doo in the handle area. It might help to spread the weatherstrip open to see. You should be able to see if the button is long enough or it needs bent.