Textures: That thought had crossed my mind, but think about it: what makes moveable parts? Circles & arcs, what better place to put them where the body movest? (Yes the texture warps with the movement of the ironsnout, but I couldn't think of a more logical place to put them without completely destroying the general look of the Ironsnout)
Colour scheme: Copper is orange, and Iron is either dark grey or different shades of red (when oxidized). Plus my overuse of bright orange was to simulate internal combustion heat, as if the body was a boiler like a steam locomotive, or those Amish steam tractors.
My inspiration came from the Hellboy characters, Karl Ruprecht Kroenen, Johann Kraus, & The Golden Army Soldiers (Characters are property of Dark Horse, respectively).
Thanks for commenting though, how's the rifle look?