rust is always sexy in games. Tho here you have put too much rust on one spot, and also too dominant (color etc.)
there should be traces of rust near seams. The following screenie has some rust on the side walls. This is what I'm talking about. Tho this is no metal.
http://www.melog.ch/dropper/v60/screens/screenie15.jpg?Basicly I have to say: the texture is still way to lowres! you need to find a solution for that. the hull should be zoomable without to display boss-sized texels.
Also: the texture has some kind of JPG loss ambiance, was there JPG compression somewhere? If so I'd suggest to work with no compression at least until it's finished. Otherwise you are risking progressive degeneration by compression artefacts.
My suggestion is: use a big texture and UV-map the sub in a way that makes best use of the texture. side parts may use tiling, the tower etc. some untiled parts.
2nd: Add an additional texture layer to the sub, containing noting but a fine grainy, well tiling texture that will give the impression of high surface details when close up.
Don't use the emboss fx, instead you may use shadow blend fx for some stuff on layers in photoshop or gimp.
