Alright...I wouldn't clear coat it, the truck is going to be inside in a controlled environment and it wasn't clear coated when it was new. What I would is use the paint as a primer on the areas that your concerned about the pits. Let the paint set up good...make sure that it's totally dry , sand it down with 320 or 400 grit. You'll be able to use the red paint as a guide coat. Gently sand the panels and clean them off periodically...where you have pits, the red paint will be shiny until you have sanded them out....repaint the panel when all is level...let it dry and enjoy. It looks like your doing a good job, don't bother with the clear coat and or the super fine 800 and 1,500 grits.