This is a simple model, designed to be a single print which includes both the skin and the frame in one.
You'll need a really nice first layer to get this to work nicely, and see what first-layer pattern works best. I found that Hilbert Curve was no good at all unless it was thoroughly over-extruded, but Rectilinear and Monotonic worked quite well.
Pausing the print after the first layer or two means you can set up a nice contrast for the skin.
The author marked this model as their own original creation.