This is a case/tray for the Corne v3 (although it should fit all variants). There are options for both choc or MX builds, and with or without optional tenting.
The Choc version uses M2 heatset inserts in the base to fasten the plate to the bottom. Alternatively you can use 3mm foam to line the rim inside the case to use as a tray.
The MX version uses M2 heatset inserts in the switch plate to fasten the bottom to the plate. Alternatively you can use 3mm foam to line the rim inside the case to use as a tray.
There is another MX version which is a little bit chunkier around the mid section. It supports both tenting and underglow. It can be used with the 3d printed switch plate or with the FR4 switch plate and M2 standoff/screws.
The inserts are not required. There is a new MX plate version that does not require inserts. You can also use 5mm standoffs or just 10mm M2 screws. Should work fine.
10mm M2 hex screws are recommended.
The tenting versions use M3 inserts to attach your favorite tenting legs to the base.
M3 Inserts:
https://www.amazon.com/dp/B07LBRB5HL?psc=1&ref=ppx_yo2_dt_b_product_details
M2 Inserts: https://www.amazon.com/gp/product/B08ZJ5WHYN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The author marked this model as their own original creation.