Re:
I was hoping someone more knowledgeable would pitch in, but it doesn't look as though they're going to.
I know you can mess about with some forks, swapping parts from different models to modify or upgrade them, change the travel, etc.. However, as far as I know, RST 461s are pretty basic, essentially just a spring in a tube, and as such, other than firmer or softer springs to better suit your weight, I'm not sure what you could do.
A good clean and a re-grease wouldn't do any harm. You could probably do a more thorough job than this guy: [youtube]https://www.youtube.com/watch?v=2eoE3iMyr50[/youtube]