(3) An offence under section 29 shall be punished on summary conviction, on indictment or in either way according to whether, under Schedule 3, the substantive offence is punishable on summary conviction, on indictment or in either way; and the punishments which may be imposed on a person convicted of an offence under that section are the same as those which, under that Schedule, may be imposed on a person convicted of the substantive offence.