Originally Posted by isthisusernameavailable

Thanks for the feedback! Will probably iterate the design based on comments.
Should be easy enough to secure in place by tweaking the dimensions to be a hair thicker for a tight fit.

If there is enough interest and feedback, a revised design could be made available for commercial printing, with higher tolerances and smoother surface finish.

This mockup was printed from PLA (kind of like a corn-starch based filament) on a 3D printer and painted black.
Painting is not typically required though, since a variety of colors and materials are available, even glow in the dark.
Used some CAD software to draw stuff up. If you are not familiar with any CAD programs, SketchUp would be a good (and free) place to start.