I was inspired by the SiCK-68 but wanted a tenkeyless layout, so I designed it from scratch.
Here are some other features I added in my design:
Case holds plate at a slight incline
Threaded inserts are used for the case-closing screws
Provision for 4 8-neopixel strips inside, for some mood lighting (but I didn't actually install them in my keyboard yet)
I used zero top and bottom layers for the top parts, hoping that it will allow the LEDs to shine through better.  The infill is 3mm grid.  This seems to be fine for strength, the top/plate doesn't deflect appreciably when typing normally.
If you follow my recommended wiring plan, you will need 20 I/O pins for the matrix; a simpler plan would use 23 pins, but that was more than were available on the controller I wanted to use, the Adafruit ItsyBitsy nRF52840.  20 pins still leaves one free for driving NeoPixels.  I chose KMKfw, a Python based keyboard firmware, and hope to enable BLE HID in the future.
Recommended construction order (which I did not follow, lfmf):…