The bonds of the authority shall be signed by either its president or its vice-president, as shall be provided in the resolution under which the bonds shall be issued, and the seal of the authority shall be affixed to the bonds and attested by its secretary; provided, that a facsimile of the signature of one, but not both, of the officers whose signatures will 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 signed either manually by, or with a facsimile of, the signature of either the president or the vice-president of the authority, as shall be provided in the resolution under which the bonds shall be issued. If after any of the bonds or interest coupons thereunto appertaining shall be so signed, whether manually or by facsimile, any such officer shall, for any reason, vacate his office, the bonds and interest coupons so signed may nevertheless be delivered at any time thereafter as the act and deed of the authority.