This is a Corne v2.5 PCB from Keebmaker (originally by foostan)
https://www.adafruit.com/product/805 for the switch
https://www.amazon.com/dp/B08214DJLJ for the battery
I've added 10 & 15 degree tents as well.
I used M2.5x10mm screws, M2.5 nuts, and M2.5 heat-insert nuts to connect the Top and Base.
I used simple 3M picture framing velcro to attach the battery to the base so I can remove it easily if I ever switch cases.
There's a push-fit window for the switch to sit in.
The downward-facing LEDs bleed through the case so a transparent material would look really good. May reprint with transparent filament.
Credit to https://www.thingiverse.com/thing:5027615/files for making .step file available, which I heavily modified. So much that it's hard to call this a ‘remix.’
Mirror the files for the left side.
Update 9/7/2023: I made the thicker variant which is much more sturdy and is built for M3 inserts instead of M2.5.
The author marked this model as their own original creation.