Depending on the engine you're using and how flexible it is, you could try using your AO as a mask, like this: (the in-game example is rather crud, this image is oldddd)
Whoa, what's with the criticism. I thought the op is advertising his 3D printing service and showing off an example from an artist who bought and paid for the service.
Nice little Mech dude :) , I think it would be cool (just my own opinion) to make it with some kind of purpose, for example, a Medical Unit or something.
You can use the Multi-switch node from the library. That will allow you to switch between colors you plug as inputs and feed that color into a mask for example.
Instead of rotating object you could rotate gizmo. For example in 3ds max when cylindrical projection selected you manipulate gizmo like a usual object:
That's a really good example, specifically because it has also been worn down and rounded out by the constant pounding of the ocean, and yet it even remains angular and jagged.