The T style rubber door strap slides in through the wooden B pillar from the back side. Unfortunately the aftermarket straps are mostly rubber causing
them to severely stretch. Original ones had fabric inside. You will need to remove the rear quarter upholstering panel. Two machine screws hold a
saw tooth bracket over the strap through the hinge side of the door under
the door panel. After market straps tend to buckle and fold when closing
the door. If your door should open when heading down the road that strap will
stretch and not hold. Lots of damage will occur. I've done three 3w with one
being a dearborn. Lucky to find a nice original. Sorry no pictures.
Here's a picture of the check straps, clamps and bezels. The bezels attach to the back side of the B pillar. They prevent the strap from causing damage to the wood structure. These straps are stiff with no give, dam near structural, no way they are going to flop around. The door pulls them out and pushes them back in.