This is a BATTLESUIT figure by Pinnacle Entertainment Group, standing next to the lovely Laura Krupp! Aside from the base, no modifications were needed. A useful feature of the figure is that the weapons are cast separately and come with a small variety to choose from, or make your own. Arm it as you see fit.

A third arm was mounted on the back so a harpoon launcher could be added. The steam hose is everyday copper wire, which was primed black and painted copper. 

This was the prototype of a powered frame contraption planned for a U.S. Marine Corps VSF unit circa 1890. A rocket launcher or auto-loading cannon would replace the harpoon launcher.

Intended as a dinosaur hunting powered frame. My, those raptors look hungry.