I still have one of the small folding C-ration can openers that came with the package...don’t know the vintage on what we were eating, but I acquired the opener in 1959. For a long time I had it on my key ring, until I figured out that must be what was wearing holes in my pocket :)
That be a P-38.
For a long time after I got out of the Army and worked in a machine shop I had one of those can openers. I had a Kennedy machinist’s toolbox with all the drawers in it, and had a C-Ration can opener in the top small drawer. I’m sure it’s out in the garage somewhere. ;o)