This a was a relatively simple model. I actually folded a crane to be able to measure the geometry. I placed points on the Planes at a Distance from the XZ plane and connected those points with 3-D lines to create a wireframe of the bird. I Used Fill Surface to create the paper planes and then used Thicken to make solid geometry. In the case of the wings, I used Move Face to extend the edge of the wings. Then I United the shapes and Edge Blended the corners. I used Control J to color the model white like paper.
You get your .PRT download below: