(1) Bonds issued under this subchapter may be executed by the manual or fascimile signature of the mayor of the city but must contain the manual signature of the city clerk of the city.
(2) Coupons attached to the bonds shall be executed by the facsimile signature of the mayor of the city.
(3) In case any of the officers whose signatures appear on the bonds or coupons shall cease to be such officers before delivery of the bonds or coupons, their signatures shall nevertheless be valid and sufficient for all purposes.
(4) The bonds shall be sealed with the seal of the city.