Well you think you have a problem, i have a Scorpion pistol with no stamps at all non on the cylinder or on the barrel, Have been told it could have been given to one of the staff as a leaving present,but no one sure.They got up to a lot of funny goings on in them days,one of the common things was to just mix any parts together mk1 and mk2 bits "etc".Some have texturing on the grip were your thumb sits,others not so.: