Unfinished state, the top cover is missing, the space for the PCB is too small, it is too large to be printed as one piece and my attempt to assemble it from two pieces did not go all that well. But it is usable and feels great.
The FreeCAD file is included.
Inspired by https://www.printables.com/model/310754-thinkpad-bluetooth-and-usb-keyboard
Needs anti-slip feet on the bottom. I bought them in sheets that you can cut by yourself.
Also needs one of the screws for the screw post on the bottom of the keyboard.
There should be more space on the sides to leave room for a top cover. In the current state the keyboard keys are very close to the outer wall.
The author marked this model as their own original creation.