"A person commits an offence if, without the authority of the [Secretary of State], he has in his possession, or purchases or acquires, or manufactures, sells or transfers- (a) any firearm which is so designed [as another object]."
"In this Act, the expression 'firearm' means a lethal barrelled weapon of any description from which any shot, bullet or other missile can be discharged and includes - (a) any prohibited weapon, whether it is such a lethal weapon as aforesaid or not; and (b) any component part of such a lethal or prohibited weapon ..."