Paint preservation

I’m looking for recommendations for products to preserve the original paint on a ’70T, Pastel Blue. Overall the car looks very good but the original paint is soft, of course, and very thin to non-existent in a few places. I do not plan on repainting so therefore am looking for guidance on getting the best shine out of the old paint. I’ve tried a number of things over the 8 years I’ve owned the car but knocking back the paint with higher cut compounds seems to be the only way to get much shine back but that is not a path to pursue for such old, thin paint. The car hasn’t seen enough care in the last three years so I am playing catch up to get her looking good again. Currently, after cleaning with clay, the paint exhibits water spots either from acid rain or just not being dried after using lousy water and is quite hazy/oxidized in large spots in most any light.

Does anyone have any recommendations for cleaning up the paint, and a top coat for preservation of the existing finish without using anything too abrasive? There simply isn’t enough paint left to be cutting much more.

Thank you.