I liked the idea with Cubic Trisection by OSKAR
, and I thought - why not cut a cube into 4 parts? We will get 4 pieces of different shapes, it will be more puzzling.
My cube has a size of 50 mm, red and blue parts are identical, but directed to different sides. Same with the white and green. Wall thickness - 1 mm, useful volume - 29.2 cm^3. It will cost about $41. I still didn't uploaded it.
What is your opinion, colleagues?