The rotary encoder crank arm comes from the USB HID Crank Controller guide.

The box has a circle cut out on one side for the rotary encoder, and a rectangular cutout on an adjacent side for the USB cable to be plugged in. It was printed with supports enabled due to the overhang on the USB cable cutout.

The lid is friction fit to the top of the box with the tabs in each corner. It's slightly rectangular so if it doesn't seem to fit try turning 90 degrees.