I really can't see any rust. The areas are leading edges of panels
that are constantly sandblasted by rocks. Each area is a couple square
inches, and I'm pretty sure it is bare metal.

It's just that "prime and paint" thing that people tend to "breeze
over". That's where I need details step by step instructions.

I'm sure that there is more than:

1. Spray on some primer
2. Spray on some paint