>>1010529
I don't think you'd need to redo the mapping. For now I would give that mesh three material slots, and setup each one like picrel, each with one of the three textures. Then I'd assign the eye material to the eye, the face material to the face and the outline material to the outline if there is one, if not just ignore it.
Using L helps to select meshes that are separate from others, like the eyes or outlines.