Hey Gerry -
Just want to make sure I understand you correctly. Are you using some kind of star ground/ground buss that ties EVERYTHING to ground at either the PT or the filter cap? If that is true then you are fine the way you are. IMO it is best to not have any redundant ground. I think it works out good for you that the chassis IS painted. As you say, just scrape off the paint at your two ground points and you are done.
If, of course, you were planning to ground the pots and jacks via the chassis, then you have a problem. But something tells me you have it all figured out to perfection.