First uploaded thing here, go easy on me :)

Pretty close to original shell.
Should work ok with all GB/GB Color PCB's.

I've printed with 0.12 layer height (first layer 0.2)
The top part has two corner tabs to prevent warping. Easy to cut off with knife after print.
There are no holes for the center screw. Make them with a drill to fit your size.

Let me see some cool color combinations! (top/bottom)