The bonds bearing the signatures of officers of the Board in office on the date of the signing thereof shall be valid and binding obligations, notwithstanding that before the delivery thereof and payment therefor any or all persons whose signatures appear thereon shall have ceased to be such officers. The validity of the bonds shall not be dependent on nor affected by the validity or regularity of any proceedings to acquire any project financed by the bonds, or to refund outstanding bonds, or taken in connection therewith.