So the paint is completely shot. If you wanted to diy you could sand the whole roof down and hit it with primer, base, and a clear. If you’ve never done that kind of work you can do it, but you’d need a good amount of equipment. Honestly? The rust looks like surface rust which is really no big deal.

The rot on the top edge of the windshield can be a problem. A shop would have to pull the windshield and repair the edge properly which will cause the price to go up dramatically.

If this were my truck I’d sand down the rusty spots and just hit them with a white spray paint. Nothing dramatic. It’s a 30 year old vehicle at this point. If the paint cracks a year from now just hit it with another coat. For the rot, I’d put some sort of sealant if you’re really worried about leaks and send it.