A texture update. Still have some UVs to adjust. This is a test render in Vue Infinite. I did end up breaking the roof object into separate parts and texturing each piece using its own technique. I thought I could get away with leaving the entire roof as one object and hand painting it in 3DCoat, but it became difficult to manage and didn't allow for further mesh editing. Carrara's Anything Goos plugin added the procedural aging and the Baker plugin did most of the heavy lifting (baking out texture maps).
There's still the entire elevator shaft left to model. This is a lot of work so far on just a background model that will be viewed at quite a distance from the rendering camera for the final scene.