Hardtop repair preparation questions

[68ls1]

My hardtop is going to need a restoration, the previous owner had made some modifications, see photos. Can anyone think of what it may have been with four hinges on roof, a large square access hole and a supporting brace?











So some questions I am hoping you can help me with
When the factory paint the roof is the texture in the paint or is the texture applied and then painted?
I am hoping we can remove paint and texture by either soda blasting or dry ice blasting. Has anyone utilized either method
Should I leave hardtop on Blazer with paint removal and doing the larger repairs to hold it rigid? Then remove to get the fiddly areas and any smaller repairs. Then paint off the car.
If I understand after paint removal I will end up with a relatively smooth fiberglass surface to which I apply texture and paint.

The good news is one of my friends is a top class fiberglass guy, as long as i can convince him to do the repairs