72 Pa. Stat. § 5878e
Whenever any city of the third class, having purchased real property for non-payment of taxes, shall have heretofore sold any such property under the provisions of the act, approved the twenty-third day of June, one thousand nine hundred and thirty-one (Pamphlet Laws 932), known as "The Third Class City Law," in the mistaken belief that the provisions of said act were required to be complied with notwithstanding the fact that the provisions of said act relating to such sales were repealed by the act, approved the twenty-first day of May, one thousand nine hundred and thirty-seven (Pamphlet Laws 787), as amended. All such sales heretofore made in compliance with the provisions of the said The Third Class City Law are hereby ratified, confirmed and validated and the title to any such real property purchased by any person from such city and the deed executed and acknowledged to such purchaser is hereby declared to be as valid as if such sale shall have been made under, and in compliance with, the provisions of the said act, approved the twenty-first day of May, one thousand nine hundred and thirty-seven (Pamphlet Laws 787), as amended.
72 P.S. § 5878e