My dad who was born about the year 1900, used to speak of a weapon favoured by the IRA during the 'tan war' called a 'parabellum'. I think it was a machine pistol and had a detachable stock which allowed the user to aim it like a rifle or to fire it one-handed. From memory it looked like a German Luger. Dad often mentioned the 'Peter the Painter' as well. I'm not sure if the two names referred to the same gun or not.