I took the original file and modified it for use as a refrigerator magnet. I took the model and sliced it in half, added a cutout for a magnet and filled in the bottom cutout.
The cutout for the magnet is designed to fit a 9.53mm OD x 3.18mm ID x 1.53mm thick (.375" OD x .125" ID x .06") magnet.
Needs supports for the hand and arms. Needs some decent cooling to get the chin done right, or tree supports.