Ctbram, I feel I should try and contribute. I don't model and extrude from one piece, but that is my preference. But I agree think that if you select the faces of the parts you want to map differently, I think that it work. At least as a planar. I would have to see it to get a feel of how to map it. I would be more than happy to look at it and give you what I think I would do. Just wanted to offer to help!