Any instrument in writing affecting the title to real estate within the state of Iowa, to which is attached no certificate of acknowledgment, or to which is attached a defective certificate of acknowledgment, which was, more than ten years earlier, recorded or spread upon the records in the office of the recorder of the county in which the real estate described in the instrument is located, is, together with the recording and the record of the recording, valid, legal, and binding as if the instrument had been properly acknowledged and legally recorded.
Iowa Code § 589.3
84 Acts, ch 1090, §3; 91 Acts, ch 183, §13