Currently at v1.0
Print at 0.28mm layer height (base is 0.84mm = 3 * 0.28mm)
Peg goes into slot on trigger behind the screw post (limiting the return travel and therefore the distance required to release the catch from starting position). Then put the screw back through the hole of the piece and into the screw post. Make sure to not tighten the screw too much or you will restrict movement of the trigger and may cause binding.
The author hasn't provided the model origin yet.