1930 Roadster Upholstery Mystery

[farmerdick]

I am redoing the upholstery in my 30` roadster. I did not make enough notes on the front back rest where the material transitions at the top of the seat to the (2) metal seat supports, where the hardwood trim wraps around. I know how to attach the metal supports but do not remember how the material is attached. There is also another separate piece of material that ties in with the seat. I have included some photos that might help. Any info or detailed photos of how this part of the installation would much appreciated. Thank You.