It occurred to me that the short one could have been used as a man trap; but then I considered the loss of such a weapon to it's owners and I discarded that idea.
I would guess that both are center fire weapons, but I don't see any mechanism to fire them, nor obvious firing pins present as they are now.
I'd imagine that the 37 cartridge would hold a heck of a lot of large buckshot.
I'd be willing to bet that the Lantaka has also been modified for a foreign round much as the 1873 MAS revolver was modified for 45acp in WWII.
A little more complicated in this instance.