All bonds heretofore issued for the purpose of financing or aiding in the financing of any work, undertaking or project by any public body to which any loan or grant has heretofore been made by the United States of America through the Federal Emergency Administrator of Public Works for the purpose of financing or aiding in the financing of such work, undertaking or project, including all proceedings for the authorization and issuance of such bonds, and the sale, execution and delivery thereof, are hereby validated, ratified, approved and confirmed, notwithstanding any lack of power (other than constitutional) of such public body, or the governing board or commission or officers thereof, to authorize and issue such bonds, or to sell, execute or deliver the same, and notwithstanding any defects or irregularities (other than constitutional) in such proceedings, or in such sale, execution or delivery; and such bonds are and shall be binding, legal, valid and enforceable obligations of such public body.