By chance, I picked up a resin cast Neyo head off ebay. It was meant for 12 inch figures but I figured it could be used with the GG bust.
The body is a regular EP3 clone trooper body, arms came from a Kotobukiya EP3 Clonetrooper and the resin head.
The right Koto arm and hand was repositioned so that it would bend a bit. Once you remove the rifle from the hand, it left a big hole which you will need to putty over. Straps, buckles and the brown parts were scratchbuilt from foam sheets and other 12 inch action figure parts.




