These units don't have a very thick layer of paint to begin with, in fact as far as I know, this is only what is called a first stage paint, meaning that there's no clear coat protection on them. With that in mind, I would first try Meguiar's Flagship Premium Cleaner/Wax. This is a great product and use it as a top finish product on many oxidized RVs that I detail.
Try using the least aggressive first. As far as the graphics, remove them with a heat gun, and head down to your local sign shop for some ideas.