To look for rust? Had a look in the top from both sides and it looks solid. No bog around the aperture either. Some signs of repair in the bottom corners looking from Inside, rough but good enough for an old truck.

I will have to eventually take both screens out before topcoating, I just know there's some nasty stuff around the windscreen, perhaps not rust but caved and paved panels. The 1/4" of bog on the A pillars where there was no damage makes me thing it was blended Into the front aperture.

Perhaps Il just close my eyes and block my ears for a while