Here are some photos of how the door handle linkage is supposed to be hooked up for reference:

At the inner door handle:


In the middle of the door:


As it enters the door cavity:


Looking up at the L-arm attached to the inside of the door from just under where the inner door handle linkage enters the door cavity:


Looking back inward at the L-arm to illustrate how the two inner door handle linkages attach:


Looking up at where the outer door handle linkages attach. The smaller rod in the foreground is the lock; it attaches in a similar manner to the other linkages. The larger rod in the background attaches to a plastic clip in the handle. The clip clamshells around the threaded part of the rod; there is no nut. The threading is to provide a positive grip along the length of the pushrod.