Mo. Rev. Stat. § 348.135

In case any of the commissioners, executive director, or officers of the authority whose signatures or facsimile signatures appear on any notes, bonds, or coupons shall cease to be such commissioners, executive director, or officers before the delivery of such notes or bonds, such signatures or facsimile signatures shall, nevertheless, be valid and sufficient for all purposes, the same as if such commissioners, directors, or officers had remained in office until such delivery.