21 Pa. Stat. § 274
That in all cases in which writs of scire facias sur mortgage have been issued subsequent to the passage of an act, entitled "An act relating to the service of certain process in actions at law, and the effect thereof, and providing who shall be made parties to certain writs," approved the ninth day of July, Anno Domini one thousand nine hundred and one, and prior to the passage of this act, and where by reason of the death of the original mortgagors intestate, and no administration had upon their estates prior to the issuing of the writ of scire facias, or where they, being non-residents of the county wherein the mortgaged premises was situated, had aliened the same prior to the issue thereof, no service of said writ was had upon said mortgagors; but in which the affidavit required by division ten of section one of said act of July ninth, one thousand nine hundred and one, has been filed with the praecipe, and service of the writs of scire facias duly made upon or accepted for the parties named in said affidavit as the owners of the premises described in said writ, and the real estate, bound by the liens of the mortgages upon which said writs of scire facias sur mortgate issued, has been sold by the sheriff of the proper county by virtue of writs of levari facias awarded upon judgments entered in such actions, the sales so made shall and the same are hereby declared to be valid and effectual to vest in the purchasers at such sales the title to said real estate, with the same force and effect as if service of the writs of scire facias had been made upon the original mortgagors, or their legal representatives, in accordance with the acts of assembly in force prior to the passage of said act of July ninth, Anno Domini one thousand nine hundred and one. Provided, however, That this act shall not apply to any case which shall have heretofore been judicially adjudicated.
21 P.S. § 274