Sorry for the double post, but I did it to separate the two parts of the topic. Here is how I have built from scratch my wife's blaster. As several models exist so I went on my own interpretation.
I used a low quality airsoft gun (5,99€ - $6,6) and some PVC leftovers (flat strips, U-bracket - hoses ...) From the gun I have kept the butt and the bottom of the body with the trigger. I glued several PVC flat strips to build the square nose of the blaster and a I have cut some U-bracket lenght under the nose extend the trigger guard.
Then I have hacked to prepare the support of the barrel with the U-bracket
and I have built the barrel and bolt with PVC tube
I then prepare the tubes on the sides from rigid PVC electrical conduits
Then I have trimmed and glued a piece in a PVC foil that comes above the barrel and the bolt to give a relief
The last step is the painting. The blaster is suspended, then I have applied a primer, and a first layer of paint in a metal color.
And last Paint it Black ! (Mike Jagger out of my head )