261.—If any person, without lawful authority or excuse (the proof whereof shall lie on the accused), has in his possession any certificate of discharge of any member of the Defence Forces or any other official document issued in connection with the mobilisation or demobilisation of any part of the Defence Forces or any member thereof, such person shall be guilty of an offence under this section and shall be liable on summary conviction thereof to a fine not exceeding F385[200] pounds or, at the discretion of the court, to imprisonment for any term not exceeding six months or to both such fine and imprisonment.