Not bad dude. My only comment would be that with the textures he's looking quite flat. Maybe it needs a better AO, or just to go in with a soft brush and paint really soft shadows on an overlay layer or something. Good stuff though.
Right now it looks like you just photo sourced the textures and slapped them on. Try baking out an AO map to get some lighing in there or else it looks flat. Suggest looking at Racer's painting metal tutorial and the other tuts he has on his site. Also look at some references for natural damage like rust etc.
I recommended you using a blue version of the diffuse for the reasons mentioned in the thread I linked, there are technical aspects that justify using complementary colors for non-metallic materials but still it's just a starting point. The difference is that you inverted the colors, inverting shadow information as well.…
Thanks for the feedback everyone BigJohn: Not too sure whether you're referring to the actual texture itself or the final render of it, I think maybe rendering it out again might help, it is very flat due to whatever setting I used at the time. Marine: I looked at a few spec maps done for characters and they all seemed to…