If you want to customize the box design, use the "Outer case blank" box file. My technique is to create a design in Inkscape, export it as a .SVG, import it into Tinkercad, make it into a hole, and subtract from the case.
Finally, the upper 2 bolt holes on the inner case are somewhat misaligned. Just use the lower 2 for now.
I painted the body and base with metallic silver acrylic paint, then washed in black and wiped off highlights. I painted the wings in metalic bronze acrylic paint and curved them gently by placing on a curved surface and heating with a heat gun.