First: What did the stain come off of? It will continue to stain until
you replace the cheap fastner or whatever that is causing the problem.

stain...
oxylic acid or brandnames using it

chalking...
"fine" (or "super fine" - go for the finest they have) rubbing compound
from the auto supply store; use a buffer machine or your arms'll fall
off before you're done.

But buff only enough to get a good finish - you can go through the gel
coat if you try hard enough. Do it for a few seconds only in a small
area, wipe clean to check your finish, and buff again and check, until
you get some idea how much buffing is needed to get your finish. Then
you can do the rest of it with some confidence. Waxing after is a good
idea if you've got any ambition left.


Rufus