Guns-N-Gear

Hello,
someone is able to add the lacking parts of the glock model present here?

Enjoy

I'm looking for the files to print custom grips for it and replacement parts

I need an idea for how do measure or record a gunstock, especially the back part, without a 3d Camera.
I thought about cupperthread, but it is to expensive.
I am looking for something that is dynamical, but stay in the shape i bent it to.