Amendments not to render invalid notifications, orders, etc., issued before commencement of Act

The provisions of this Act which amend any Act specified in the Schedule so as to alter the manner in which, the auhority by which, or the law under or in accordance with which, gny powers are exercisable, shall, noL render invalid any notikation, order, comrnitrrtent, attachment, by-law, rule or regulation, dul'y made or issued or anything duly done before the commencement of this Act; and any such notification, order commitment, attachment, by-law, rule or regulation or thing may be revoked, varicd or undone in the like manner, 10 the Iike extent and in the like circumstances, as if i t had been done after the commencement of this Act by the competent authority and in accordance with the provisions then applicable to such a case.