So going to be repainting the exterior of my FJ60 in the next month hopefully. I have been in the process of replacing all rusted out EXTERIOR metal and am down to one last location before I do the swap (well and swapping one more door out). Question is.... At this point when I am ready to prep for paint, should I; A.) just rough surface of all currently painted/primed surfaces and then spray the single-stage over it, or B.) rough all surfaces, lay down a layer of new primer over all surfaces and then spray single-stage? If I go with option B.) I take that as meaning that I should really wetsand the primed surface down with 320grit to come up with a smooth surface, then proceed to the single-stage. I do not plan to take anything down to bare metal other than those locations needed to correct/repair rust. This will be my first go at auto painting and will be an adventure/experiment.