All proceedings for the creation of sewer districts and for construction of sewer and water improvements under sections 6117.01 to 6117.45, inclusive, and 6103.02 to 6103.30, inclusive, of the Revised Code, prior to May 10, 1927, and all petitions granted, or the letting or awarding of contracts, or all contracts made and entered into, or proceedings preliminary to or in connection therewith, or certificates of indebtedness or bonds issued or to be issued or taxes and assessments levied or to be levied on account thereof, are hereby declared to be valid notwithstanding any defect or irregularity therein or any failure to conform strictly to sections 6117.01 to 6117.45, inclusive, and 6103.02 to 6103.30, inclusive, of the Revised Code. In any proposed district where the contract has not yet been let, the proceedings shall not be ratified unless state land to be benefited shall be included therein, with the power to assess such state land in proportion to its benefits the same as land privately owned, including the cost of preliminary surveys. Boards of county commissioners or other officials may complete all improvements in process of construction under such sections, levy taxes and assessments for such improvements, sell bonds to pay for the construction of such improvements, and do all things contemplated by such sections necessary for the completion of such improvements.