The bonds, certificates and promissory notes of the authority shall be signed by either its president or its vice-president, as shall be provided in the authorizing resolution, and the seal of the authority shall be affixed to any bonds so issued and attested by its secretary; provided, that a facsimile of the signature of one, but not both, of the officers whose signatures shall appear on the bonds may be imprinted or otherwise reproduced on any of the bonds in lieu of his manually signing the same and provided, further, that a facsimile of the seal of the authority may be imprinted or otherwise reproduced on any of the bonds in lieu of being manually affixed thereto. Any interest coupons applicable to the bonds shall be executed with a facsimile of the signature of the president or the treasurer as shall be provided in the authorizing resolution. In the event that, after any of the bonds or interest coupons thereunto appertaining shall be signed by any officer of the authority, whether manually or by facsimile, any such officer shall for any reason vacate his said office, the bonds and interest coupons so signed may, nevertheless, be delivered at any time thereafter as the act and deed of the authority.