Does any one have any tips and tricks to clean up the finish on these guys pictured below.

There are guys here that really have that down pat. I'm sure they'll chime in. I've cleaned up several pair myself. Here is a high level overview for me: They have clear coat on them from the factory. Once it gets warn and chipped/scratched then the aluminum underneath corrodes. So first thing to do is remove all the clear coat. I wet sand them with 600 grit to remove the clear and work out the scratches and gouges. Then the work begins. More wet sanding like you would if finishing a fancy paint job. Up to 3000 grit. Then polish with your favorite metal polish. I use SemiChrome or Mothers Mag and Aluminum Polish. There are many metal polishes out there. I don't put clear coat on mine when done. I leave them natural and shiny. So far they've been staying that way. Others may apply a clear coat? Hope that helps!

I use 3M Scotch Brite nylon pads (I usually end at "very fine" grade 7447) and leave some sanding marks on them. But you could do as above and polish to a mirror shine if that's what you're going for.

7447, what about equal to in sandpaper grit.

320 I believe

Edit: Oops, it's equivalent to 360-400 grit sandpaper. Here's a pic I found of 3M's grit chart...

thanks. sound like a good bit of elbow grease is all that's needed.
I have a 73' ATMX. I'm restoring it to original. Does anyone know if they had that mirror finish on a brand new bike?

On my RT2 I took note of the original finish (direction/grain) under the clear coat and the 3M 7447 got me closest to OE (to my eye anyway). I'm not sure if the ATMX had a different finish on the fork lowers, but my guess is they were all finished about the same.