It took a while to figure out how to put it together, but I got it working. Hopefully my pictures will help others understand what to do.
For the “toothpick”, I printed the 6cm stick from voltronwanted’s print profile, but I cut off about 2 centimeters to get it to fit inside the back chamber. I used super glue for gluing plastic together, and I used hot glue for gluing the spring, and I also hot glued fishing wire to the bottom of the shooter.