A Tiny Knife Case XX M5F Circa 1950s

Well I think it is a Case XX M5F. There is a bit of corrosion so it is hard to tell. It is very small for a fixed blade knife. The blade is 3" and it is about 6 3/8" overall. It is in rough shape so it is not collector grade but would look nice in a curio cabinet.
In photo #3 it is between a Boy Scout knife and a Ka-Bar, the Ka-bar being the largest and the Case being the smallest.
The advantage to this knife over a folding knife is that it is a bit stronger (not counting locking blades). Were one to layer their blades I would carry this along with the Ka-Bar and machete or other chopper. Perhaps a bazooka to finish the ensemble.