The cabin roof was too badly damaged, so we built a replacement. First steel bars were notched, then bent and welded to form curved beams. These were then welded to a sheet of steel, forcing it into a curve across the roof section
Turning this over, slots were cut across the roof at intervals. When welded up, these slots pulled the roof into a curve along its length forming a compound curved roof panel.
A trial fit, a bit of a trim, then welded into place.
A couple of strips of "rivets" down each side, and the roof is on, with a very pleasing compound curve.