Yesterday we finished stripping the rest of the truck bed and exposed more hidden surface rust, so the bed is now in better condition for painting than it was before I P-15ed it the first time, we also decided that we will not be por-15ing the entire bed. Instead we will be using self-etching primer then a high-fill primer before painting over it with the final "auto air colors."
In addition we used some metal-filler (not bond-o)on the tailgate which had several nicks and dings on it. It took us some time to figure out what the proper proportion of filler to hardener was, but we finally figured it out [just a smidge of hardener to a 3x2" section of filler] and sanded it smooth. It turned out pretty well for our large learning curve. Next, we used our high-fill primer and made it look excellent! Don't worry, there will be plenty of other opportunities to show the filler process later when I will have a camera.
I am feeling excited about preparing to paint! Blocksanding and priming: watch out! here we come!