For the Dementor SS are these aluminum roofs. In three flavors the Little G, Big G and the DUV. Mount them on the outside of the chassis and give them a little pinch on the top. If you mount then to the inside of the chassis you will need to remove 3mm of material from whatever brace or panel you choose to use.
The Little G will need some light sanding but I’m pricing them accordingly
All will require crossmembers or roof panels to complete.