Hi,
This car is in nice shape with no rust holes. It was a dry California car. That said the paint is very thin and it has a lot of areas with surface rust coming through the paint all over. How should I get the surface ready for paint? How do I treat the rust that is on the surface of the metal. Could I DA the whole thing then epoxy prime the surface and then filler and primer and topcoat?

with out seeing the car you could just da the old paint and do as you suggested shoot some epoxy over it, but that's probably not the right way to go. that paint could be 62 years old almost as old a me. I would sand it all off and start with clean bare metal. see how it gos if the surface rust is light you might be able to just sand it off clean. not being able to see it its hard to tell. post some good pictures.
Jay D.