No background image. Don't make your art fight itself. Make the background rgb 42 42 42 and work your Specular, take all that grime layer in your diffuse, throw it in your specular and crank the contrast. that will sell it.
[..]23 42 ? Hey, that's the two numbers I use as placeholder integer values. It's 23, the number of the Illuminati and 42, the Answer. But 48, 15 and 16?