Sonny,
You might want to take a good look at the door latches as they sometimes wear (from the door rattling) and make the door loose(r). I had to have mine welded and reshaped. The striker plate screws are Henry's favorite, the 12-24 that can likely be found in your local hardware, even in brass. Now I'm going into dangerous territory and breaking one of the rules, namely "DON'T PULL ON SUPERMAN'S CAPE".
The striker plates are adjustable on the closed cab. The screws go into a floating plate that is in a captive device behind the B pillar.