I am writing from the road, so I can't check . . . but I believe that the door hardware is covered in the AIM. However, I had the same problem with my '75 and it was indeed the adjustment for the outside door handles . . . both doors on mine also.
The adjustment is very sensitive on the adjusting rod. A few turns can make the difference between everything working correctly or not. My problem presented this way: the doors would open unless the door was locked and then unlocked. Once this cycle had taken place, the door latch refused to work. I would have to roll down the window and use a long screwdrive down in the window channel in order to press on the actuator and pop the door open. Once this had been done, the door handle would work correctly, until the lock and unlock cycle had once again been completed. I fooled around with ONE DOOR for an entire weekend before I finally figured it out. Of course, just getting the rod adjusted a few turns and then getting the keeper in the hole in order to test it was a major operation . . . I guess my hands are too big. Anyhow, I would certainly check the AIM for correct linkage placement and adjustment.
Just my $0.02 ( from a guy that's BTDT)
