Designed an adapter to fit a different shift knob. Used PETG, however, stronger materials can be used. It is designed to have a m3x25 bolt thread in the center for added strength to help reinforce the layer lines. I used m3 bolts to secure it to the shift lever but m3 grub screws can also be used.

This is my first published design, if another thread profile is required I'll gladly add it.