Reply #3: This came up in one of Goofy's incessant threads

[Euromutt]

This one: http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=118x229108

Provisional conclusion on my part was that it was Romanian, and on benEzra's part this it's the genuine article; a selective-fire Pistol Mitralieră model 1963, or possibly 1965 (the stock was removed, so you couldn't tell whether it was originally a fixed or folding stock model).

Definitely not purchased on the American civilian market.