Update: Did the arc rail. That was a tough one, cause it was hardsurface, yet quite organic. But I'm happy with the results. Up Next: Peltor Comtac III
Some info here. http://wiki.polycount.net/Normal_Map#TangentSpaceVsObjectSpace In Max's Render To Texture, go to the Projection Options dialog, and change it from Tangent to Local (IIRC).