A rough-up of an old wooden puzzle I had growing up, drafted from memory. Cube is 40mm to a side, with 0.1mm slop allowed, which allows for a neat fit which doesn't just fall apart.
Printed 0.2mm layer hight, speed profile, on a Prusa Mini, with no supports. There's a 10mm bridge span, which my printer handles fine. I printed parts 1 thru 5 (with copies, 8 parts) in one print, and the remaining 2 parts (6 & 7), with copies, 4 parts, in the second print.
The two included gcode files print all required parts, with duplicates, as multipart prints.
Drafted in OnShape:
https://cad.onshape.com/documents/fd6eccc44141206dea4d9be2/w/8f600599e5ffe6482cb7196f/e/effed691282c82e944692806
Added an exploded view in OnShape and a screenshot here to help those who might battle with assembly.
The author hasn't provided the model origin yet.