"The provisions of this Order which adapt or modify Indian laws so as to alter the manner in which, the authority by which, or the law under, or in accordance with which, any powers are exercisable, shall not render invalid any notification, order, commitment, attachment, byelaw, rule or regulation duly made, or issued, or anything duly done, before the commencement, of this Order; and any such notification, order, commitment, attachment, byelaw, rule, regulation or thing may be revoked, varied or undone in the like manner, to the like extent and in the like circumstances as if it had been made, issued or done after the commencement of this Order by the competent authority and under and in accordance with the provisions then applicable to such a case." ·