Anodized is a process that is usually used on aluminum. You say they have rusted, so I assuming they are steel. Which lines are these? If they are steel like the injection lines, they are more likely plated with either zinc or CAD.
Yes, I use clear on plated zinc or CAD surfaces. My favorite is a clear spray made for engines which has a high temp rating and is fuel and oil proof. This will prolong the life of the coating although will slightly alter its appearance. That may be an issue with a concours car, but not one for the rest of us. The finish will be glossy if applied as normal. So what I like to do is apply a couple of light coats and then finish with a dusting. This will still protect but will give it a satin finish. Be sure to let the clear dry in between coats. I do that on just about every plated part on my car. My 2 cents worth.
