Maybe (but only if you like) some decent washes here and there to emphasize the battle damage, and thats it. Another very simple, but effective method for the last steps is the sponge method - after you brought on the washes, dip a small piece of a sponge in aluminum/chrome (depends on the look you want to achieve) and emphasize the lightest spots.
So let me get this straight....you stripped the bust? Well you certainly have conviction!! I was thinking he was looking the part for sure...but I am sure you will wrangle whatever demons in the finishes and get yourself straight with the project!! All about "learning" what to do and what you like!! Bring it on G!!