All bonds issued under Sections 65-4-25 through 65-4-45 shall be executed on behalf of the state by the manual or facsimile signature of the Chairman of the State Bond Commission and shall be countersigned by the manual or facsimile signature of the Secretary of the State Bond Commission. All coupons shall be executed on behalf of the state by the facsimile signatures of the Chairman and Secretary of the State Bond Commission. If the officers whose signatures or countersignatures appear on the bonds or interest coupons shall cease to be such officers before delivery of the bonds, such signatures or countersignatures shall nevertheless be valid and sufficient for all purposes, the same as if they had remained in office until such delivery, or had been in office on the date such bonds may bear.