Any instrument affecting the title to real property, one year after the same has been copied into the proper book of record, kept in the office of any county recorder, imparts notice of its contents to subsequent purchasers and encumbrancers, notwithstanding any defect, omission, or informality in the execution of the instrument, or in the certificate of acknowledgment thereof, or the absence of any such certificate; but nothing herein affects the rights of purchasers or encumbrancers previous to the taking effect of this act. Duly certified copies of the record of any such instrument may be read in evidence with like effect as copies of an instrument duly acknowledged and
recorded; provided, when such copying in the proper book of record occurred within five years prior to the trial of the action, it is first shown that the original instrument was genuine.