Prevent more rust, patina it?

[tj62]

Been working on my truck recently and its got 10 year old primer and no paint on it, with a lot of rust and some areas with holes in it. I'll eventually get around to fixing the body work and painting it, but trying to figure out what would be best till then.

I could go all out and sand, primer, paint with rattle can, but am kinda nervous about that or I could just sand it down a bit to get the rust off, then seal it to keep it from getting worse to "patina" it. I like the grayish color and it has some red paint underneath, possibly old primer, I see some black in there too.

What's a good way to prevent rust from getting worse, but improve the finish a little? Is there a clear, non-shiny rustoleum out there to seal it or something?

EDIT: you can see the truck in my profile, not sure how to add pics here yet.