Making the STA-52 Light Assault Rifle From Killzone

A while back, I got a message from a very talented 3D modeller named Hugh Holder who had made a pretty decent digital model of one of these:
 
 
This is the STA-52 light assault rifle used by the Light Assault Infantry troops of the Helghan Empire.  From one title to the next in the Killzone series there are some minor changes in the design, but nothing significant.

With the 3D modelling  done, he asked me if I'd be willing to build it for him.  No problem.

Here's a couple of copies of the finished piece:


To see how they were made, read on.