Star Wars was shot on relatively fine-grain stock; what we're used to seeing is not representative of the negative. Much of it comes from the prints, themselves, and there are fine-grain prints out there. But moreso, you're looking at a small crop, smaller in resolution, which of course shrinks the grain with it. But no, I don't do any noise reduction or grain removal. I do, however, use tools to recover detail from within grain structure.
_Mike