My Dad's 55 Oldsmobile Rocket 88 was a turquoise and white two door hardtop. The big woodie also has two doors and 9 inch thick hard brick arch covered with 3 inches of fiber and a hardtop made of insulating castable and Portland cement. We covered the firebox arch too. Donovan thinks this will be a slow cooler with all the mass and the insulation. Kilns are so poorly insulated these days people have resorted to firing down to get good glaze results.