Yet another question for my project tractor. I have a '70 4520 with most of the paint still on it. What i was planning on doing is wire wheeling the ligtly rusted spots (mainly the frame rails) and then shooting JD primer over the spots where the wire wheel went. The thought crossed my mind to just shoot the primer over the whole unit right over the old (still intact) paint. After the primer I would then start painting with JD paint. The sheet metal would be taken down to bare, primed, and painted. This is my first paint job so I am a bit lost. Has anyone else painted a tractor this way? Keep in mind that this tractor is still used as our main tractor.