Improved X-Acto Knife Box Inserts

The original version by MakeHer was a bit too small for the X-Acto box, so I adjusted the size a bit, and improved the slot for the big, red knife handle to fit better. I also altered the blade insert to accommodate ten 3mm x 5mm neodymium magnets, because the included magnet strip was basically useless.

I still recommend gluing the inserts into the box.