You will not find a paint code on any data plate in 52. They did not exist. I do not know when they started putting paint codes on the trucks but it was at the very least, after 54. On my truck, written in grease pencil on the underside of the hood, is written "Transport" for transport blue. You may get lucky and find something like that but that is the best you can hope for other than finding some original paint in a hidden area of your truck.
