New more better version:
https://www.thingiverse.com/thing:3178800

sheath for 3 inch Morakniv chisel
great sturdy EDC tool but the stock sheath is too bulky
https://www.amazon.com/Morakniv-Craftline-Carpentry-Chisel-3-0-Inch/dp/B00T3ES1SC
This thing is not just a wood chisel, it's a cheap-and-cheerful opener of all things closed

Please be careful - this chisel can open your finger up to the bone in a blink, and hand surgeons are expensive