Assembly: I used a 15 cm long 3/8" threaded rod, smear expoxy between two halves of the ball, threaded the rod through them and used two nuts to clamp them tight. I used a threaded eyelet and a jam nut at the end of the rod, so I can hand the ball.
Please feel free to do it in you own ways or modify the files.
The author hasn't provided the model origin yet.