Reappearing scratches

[Blackthorn One]

For a few years, a few spots on my father's black clear coated Deltron acrylic urethane 56 Chevy have been really cloudy and looked like they were severely oxidized. The car had been out in the sun for a few years and really hadn't been adequately protected. So maybe 5 months ago, I spent maybe 5 hours hand polishing a section a little over a square foot. I had all of this cloudiness completely removed to reveal deep glossy black which was basically perfect.
The car has been garaged since and only driven only maybe 6 times since, and so it has had very little sun exposure, and since I'm the only one detailing it, washing it ect, I KNOW that no physical damage has been done by any abrasive whatsoever. As of a couple months ago, I noticed that in the same area, there is a criss- cross pattern of scratches in the paint. I'm getting the car ready for a show in Oct, and really want this area done.
I can see that some or quite a few of the scratches are indeed in the clear coat, but a lot of them I really can't tell whether the scratches are in the clear, or in the black or in the primer or the base metal, and one of these layers has shrunken down to reveal scratches in the black, the primer or the metal. This area is in the CONCAVE area where the rear quarter meets the deck lid, on the top of the rear quarter. The entire rest of the area that I polished on this area-the deck lid, the rest of the quarter, as well as the rest of the car, remains unchanged. The cross hatch scratches are maybe
The car was painted about 9 years ago, so I wouldn't expect more shrinkage at this point. The car WAS driven out to desert heat one day after I polished it, which is unusual, and seemed to be the time I noticed the resurgence of the scratches, but, like I said I wouldn't expect additional shrinkage after 9 years including this additional heat.
I used System One to polish it with, which is water based. Sure, some of the polish might have hidden SOME percentage of these scratches, however these are far too deep for any polish to hide more than a quarter of.

I could polish it again before the show to get all the scratches out, but then the paint will be thinner, and what if the scratches return? I certainly can't keep polishing it if those scratches keep coming back. I plan on just polishing them a little, and then using Poorboy's Black Hole glaze to hide them as best I can, and then build up many wax coats to hide the rest. I was thinking of using Souveran for this. I have Supernatural, Fuzion, Zymol Fantasy Urethane I could use, as well as many others, as well as the Natty's Red on this black, which REALLY looks great on it as it makes it look REALLY wet and deep, as well as really pop. I'm sorry I don't have a digital camera, otherwise I'd post pics, which is why I've tried to explain it with words so much. It LOOKS like scratches on bare metal which weren't sanded finer, and then when I sanded out their appearance in the paint, the paint and primer just sank again. Could you offer me some advice?

[Mike Phillips]

The scratches are either topical, as in on the surface or under the clear. If they're on the surface you should be able to remove them if you have enough film-build to safely work with.

If they're under the clear coat then there's nothing you can do. Hard to say what's what without being there in person.

I would place a tape line down the middle of the affected area and work on just one side of the tape with something like a compound and then inspect the before and after results and you should be able to tell easily if you're work is having any kind of effect.