Sponging and scratches added for increased wear and tear. I sponged dark grey, silver and a bit of bright brown for small rusty spots. I also painted grey lines and attempted to put a thin silver line above for a dimensional look. In hindsight, the silver line should have been below the grey line, not above... still looks pretty cool, but it is backwards for a groove cut into the surface.
4 attached images. Click to enlarge.