Pictured is my Kobo Clara 2e with a laser cut leather cover hand stitched to the 3D Printed Parts and replaceable arms. So far I have the Kobo Clara 2e, Kobo Nia and the Kobo Clara HD designed. I’ve also made the parts available on
Thingiverse: https://www.thingiverse.com/thing:6340022
Printables: https://www.printables.com/model/662929
and the FreeCAD design files are on GitHub: https://github.com/the16bitgamer/16BitVirtualStudiosDesigns/tree/main/GLoA E-Reader Cases/6 inch
Here is the base frame for our 7.8" E-Reader case https://github.com/the16bitgamer/16BitVirtualStudiosDesigns/tree/main/GLoA E-Reader Cases/7.8 inch
If you need an example on how to make the arms the 6" is probably the better place to go, as it’s going to take a bit to clean up the cases.