Thanks for the great pictures,did the tag attached to the gun note anything ?
Source as in manufacture doesn't much matter,but source as from who supplied it does.
The principle of deniability in past arms trading to groups and factions in C & S America,Tibet etc and fake headstamps on ammunition is a well troden path.
Sam Cummings for one when working for the CIA and afterwards suppling them is covered in the book 'Deadly Business' which my be of interest and a bit of light reading for the 'senior Intelligence Officer'
ATB Kevin