Projects and proceedings for the issuance of revenue bonds, pledge orders, and other temporary obligations commenced before the effective date of the city code may be consummated and completed as required or permitted by any statute or other law amended or repealed by 1972 Iowa Acts, ch. 1088, as though such repeal or amendment had not occurred, and the rights, duties, and interests flowing from such projects and proceedings remain valid and enforceable. Without limiting the foregoing, projects commenced prior to said effective date may be financed by the issuance of revenue bonds, pledge orders, and other temporary obligations under any such amended or repealed law or by the issuance of revenue bonds and pledge orders under the city code. For purposes of this section, commencement of a project includes but is not limited to action taken by the governing body or authorized officer to fix a date for either a hearing or an election in connection with any part of the project, and commencement of proceedings for the issuance of revenue bonds, pledge orders, and other temporary obligations includes but is not limited to action taken by the governing body to fix a date for either a hearing or a sale in connection with any part of such revenue bonds, pledge orders, or other temporary obligations or to order any part thereof to be issued.