Simple stock mount for Dart zone villainator/Spectrum stock attachment point. Stock is attached with 3x M3 10mm bolt. Spaced evenly on 20mm circle. Version with a catch requires a spring and a 14mm m3 bolt. I was able to make it work with 10mm and 12mm bolt also. but 14mm bolt is recommended. A regular old ball point pen spring should do the trick. you will want to cut spring to about 5~8mm length. I used a 4mm diameter spring that came with the cheap ball point pen.
I have also included simple stock as an example. Stock will require 4x M3 10mm, 2x M3 20mm bolts to be assembled. Flexible filaments are recommended for the shoulder pad.
I have included the f3d file for the design. Feel free to tweak however you'd like!