Section 33. All such policies or contracts issued by such company shall be signed by its secretary or an assistant secretary, or in their absence by a temporary secretary, and by its president or a vice-president, or in their absence by two directors. Riders or endorsements, other than riders or endorsements providing for any of the benefits specified in section twenty-four, attached to policies of life or endowment insurance and annuity or pure endowment contracts, and riders or endorsements attached to policies of accident and health insurance, may be signed by one of the aforesaid officers of the company. Riders or endorsements attached to any other policy or contract of insurance need not be signed by any officer of the company if signed by a duly authorized agent or representative of the company; provided, that the name of the company shall be printed, typed, written or stamped on each such rider and the number of the policy or contract to which it is to be attached is inserted therein. A facsimile of the signature of any such officer imprinted on any policy or contract or any rider or endorsement attached thereto, or a facsimile of the signature of any such agent or representative imprinted on any rider or endorsement which under this section he is authorized to sign, shall have the same validity as his written signature.