I think a few good coats of rust preventing primer, then some gloss or matte black rustolium spray paint followed by a few coats of spray clear is the best way to go. Looks great if done properly and very easy to touch up.Lets use this thread to suggest what to use and how to use it on what part of the XK. We can start with tubed fender and rails. Steel that will see some abuse.
I had a set of N-Fab bars on my silverado that were powder coated black. They looked good when new, but after they started getting beat up from offroading i could NEVER get my "touch ups" to look like the original powder coating. I eventually just sprayed them with the gloss black and some clear... from then on they were a breeze to touch up.