Bake the normals in object space then extract whichever channel that represents the vertical axis. This will give you a good base for a zenith type of lighting and also indicate which direction surfaces are faceing on the model. Here's how I'd go about the process if that's of any help.…
That's quite a solid start. It's almost as if you could just slap colors on there and call it done. The fur still bugs me though. Maybe it's the filtering on the screenshots but it looks like you have some strands or very thin chunks defined that dissolves when zooming out. Actually, the more I look I think the problem is…