I went at if from below. Like everything else, it's a compromise. There's no one way fits all solution. For me, the difficulty working overhead was worth it to avoid matching gel coat and recreating the structure of the cabin top. I even had to scrap a large section of fiberglass due to it being too large and difficult to deal with after I wetted it out with epoxy. If I had to do it again, I'd do the same thing. As far as reusing the top skin, I don't see the advantage. If you have to glass and fair the seam, you might as well glass the whole area. I can see how some might try to keep the glass work in the area between non skid, but if you're using a proper 12:1 ratio, you're going to end up in the non skid regardless of where the repair is located. On the other hand, if you have a fiberglass headliner the compromise may weigh in favor of going from above.