Folgore,
The copper is very nice to work with because it does not "work harden" as you fold. That way, you get more tries at getting the parts folded just right.
As far as the seat back, I am going to add the small pieces of pipe that held the seat back on the rear basket... and then the seat will be in place. I thought that would look cool and show how the seats were stored.
I build most of my models in subassemblies that can be separated for painting. This model is just sitting together at this point. The upper hull can be removed to reveal the interior details, the gun assembly, the gun shield, and even the roadwheels are still easily removed for painting. That way I can get at everything for the painting.
Later,
Tim