(1) The bonds shall be executed by the manual or facsimile signatures of the chair and secretary of the board of the research park authority.
(2) In case any of the officers whose signatures appear on the bonds or coupons cease to be officers before the delivery of the bonds or coupons, their signatures shall nevertheless be valid and sufficient for all purposes.
(3) The coupons attached to the bonds may be executed by the facsimile signature of the chair of the authority.