I think you should not be looking at shaders? I think, if you don't already know how to, you should be looking at UVWUnwrap? If you don't know the UVWunrap modifier very well? There is a great 15 minute tutorial on using the UVWUnwrap in tutorials section.
I would suggest taking the approach of UVWUnwrapping it because it is a beautiful model, and you can do so much more with it if you create your textures in photoshop than relying on procedural materials.
Everything ages with time and shows some form of age and wear, you want te robot to look as though its been active with dust, dirt, grime, grease, dents, scratches or even holes etc
Obviously this will involve even more time developing its appearance but it could well pay off and you should even consider setting it when you are done in an engineering environment per se and doing a decent render and entering sending it to 3Dworld.
There is also a great tutorial on uising lights, but that depends on the renderer you're using.
hope this helps