All mortgage foreclosure sales of real property by advertisement, under power of sale contained in such mortgages, made before January 1, 1992, the sheriff's deed thereof having been executed and delivered to the purchaser of such real property before January 1, 1975, notwithstanding any defect of notice, acknowledgment of any instrument or the recording thereof, or any other defect in the proceeding, are hereby cured, legalized, and validated as fully as if such foreclosure proceedings had been made in full compliance with all existing statutes or laws.