New to the site. Love it. This is my first restore project. I have a 1959 Columbia I am restoring. It was black when I got it. I wire wheeled it down to the first coat of paint, which is kind of a royal blue. But, there's some red underneath which I'm not sure of. The blue will not come off and I cannot get it down to the metal. My question is this. Do you need to prime this first even though the original paint is present? Or do you just find the blue that it was, and do it that color to save time?