Here is my case for the Novelkeys Numberpad PCB. Cases are unicorns for this thing so I made my own. I modeled it to match my Kono Kira perfectly, and is a high profile case design so supports are needed. Flip upside down so the bottom faces up in order to keep the frame smooth, but can print both ways.
Here is a link to the PCB. It is super nice and hot swap.
Flip the case upside down and print with supports everywhere. That way the USB cutout and the lip for the PCB is supported. Tolerances are tight to pop the PCB in but it holds it nice and tight. My switches fit snug but not too tight.