Thanks for the feedback @frikker!
I actually started with Andrew Price's Dielectric PBR material with the hat, but I was really unhappy with the result. It turns out this was because I hadn't UV unwrapped my object, but anyway I switched to the Shader Forge PBR material and stuck with it.
You are right, I didn't get much out of the PBR material, but I get good Fresnel out of it without having to remember the details. In retrospect, I should have ungrouped the shader and removed the extraneous bits. And, I should definitely have plugged something into the normals.
I was tempted many times to use textures, but I really wanted to do the whole thing with procedurally generated textures. Must be the computer programmer in me.
It is a really good, and exciting idea actually try out the PBR materials on my shader!