The acts of the county auditors of Iowa, in making and recording plats as authorized under sections 922, 923, and 924 of the Code of 1897, and sections 6289 through 6299 of subsequent Codes* to and including the Code of 1939, without first having properly signed or acknowledged the same, and the acts of the county recorders of Iowa in recording such plats, are hereby legalized and the same declared valid and binding the same as though they had in such respects been made and recorded in strict compliance with law.