How did "they" get their hands on one...
Well, you see, there is this village in the Indian hinterland where the entire town is made up of smithies, a few hundred guys hand-hammering out panels and eyeballing them, then hammering some more, and eyeballing some more, until they fit together just so...
(Actually, there is a village like that in Pakistan, where they hand-make replica firearms of all kinds. Need an early muzzle-loader (they do "antiques" really well!), or an 1800s gatling gun, or a one shot spy's pen gun, or maybe an uzi or an AK 47 on the cheap? They'll do it, a visually perfect copy accurate right down to the serial number. It's called Darra Adam Khel. I've been there, and it's really a "trip", in more ways than one. Guns are test-fired into the air in front of the shops as they are finished, and test-fired again by prospective buyers, so all day the air is rent with the sound of sporadic gunfire.
There are cautions, though: the metal used is usually melted down from old car parts and other dubious sources, so occasionally a gun has a flawed alloy and will blow up when fired! Also, don't get caught taking one of the pen guns through customs when you leave, and especially not with one on an airplane; it's illegal and will give you serious trouble.)