8. I used the shader Blin and I used a map Fallof in the channel Difuse and on its black channel I used the dark texture (with a repetition tilling 5) and in the white channel I used the same texture, but lighter ton. You can use the same texture to Bump, Specular and Glossiness channels, without the map Fallof though.

9. On the hand, select the parts that won't be chromes because you will apply the shader blin or strauss without texture in the difuse channel. In any case, you must use the material raytrace in the channel Reflection. So in this specific shader you can use a black color on the Channel Difuse (pay attention if you use a Global Illumination you must use the GI's Material)..

10. As image below shows you can use the texture and can use the bump texture too.