I designed this holder to fit either 3x 221-415 or 3x 221-412 + 3x 221-413 with space for an extra if desired.
Slide them in from either end with the lever facing the shorter wall. Flip up the lever to help slide them out if needed.
I glued 2 of the slots back to back in order to have a small assortment on hand in my portable toolbox.
Note: PLA might be too brittle for this design if you want it to last. The one I printed in PLA eventually snapped along the corner of the wall, PETG fared much better.
The author hasn't provided the model origin yet.