In leui of redoing the turrets, as suggested by the Relic boards (which I'm too lazy to do atm

, but will do later), I've begun texturing with Sketchup. It's very possible and not too hard (actually sometimes a LOT easier than regular UV mapping methods). If anyone wants I can write up a tutorial.
Obviously still a WIP:

With some 30 second weathering/darkening:

I took that texture from this model:

What I did was draw all the panel lines on the model in SU, export as a 2D image, then stick all the views into a texture map.
EDIT: The reason it looks so different is because in this shot, the outlines were enabled - the texture is taken when they're disabled.