Pump up the contrast and the brightness on the specular. You lose alot of the red in your diffuse couse of the high average brightness in you specular. I really like you diffuse, but i think that the worn bits is too uniform. Make them count instead!
Someone linked a article about materials a while back. Basically from what I read..if you want the material to read as metal...the spec map needs to be close to the color of the diffuse map. That way the light that bounces will be close to the color of the metal.