This is a complete redesign of the model by David Warboss. I made it larger, and added a contour on the lower tray edge to be comfortable when resting my hand. I also experimented with a "snap-fit" new design component.

Note: due to the close tolerances of the snap-fit cover, if it is hard to close... run a razor knife along the inside of the lip on the cover to lightly scrape off some material. Do this until it snaps closed comfortably.

I will fix this in a later revision but, the small amount of post-work is not a big deal right now.

Future: I want to add a groove for a seal/o-ring (probably a TPU design)

UPDATE 11/18/2022: Repaired tray cover STL