Whenever any city of the second class has heretofore filed, in the office of the prothonotary of the proper county, any tax lien or tax liens, and the said city of the second class has not, within the period of five years after the date on which any such tax lien was filed, sued out a writ of scire facias to reduce the same to judgment, or whenever any such tax lien or tax liens have been reduced to judgment and the said city of the second class has not, within the period of five years after the date on which such judgment or judgments were entered or within five years after the date on which such judgment or judgments were last revived, filed a suggestion of nonpayment and an averment of default, or sued out a writ of scire facias to revive the same, then, in any such case, any such city of the second class may, within six months after the final enactment of this act, issue its præcipe for a writ of scire facias on any such tax lien and proceed to judgment in the manner provided by law to obtain judgments on tax liens, or in case judgment has been entered, either file a suggestion of nonpayment and an averment of default or issue its præcipe for a writ of scire facias on any such judgment and proceed to judgment in the manner provided by law to obtain judgment of revival, and such judgment, so entered or revived, shall be a valid judgment and be a lien upon the real estate upon which it was a lien at the time the lien was filed or the judgment was entered, and said judgment may be revived or further revived and collected as other judgments upon tax liens are revived and collected: Provided, however, That the lien of any judgment shall not reattach against any real estate transferred to any purchaser during the time when the lien of any such tax lien or judgment was lost, nor shall the lien of any such judgment impair or affect the priority of the lien of any mortgage or other lien, which gained priority because of the failure of the said city of the second class to sue out the writ of scire facias or file a suggestion of nonpayment and averment of default within the five-year period, or was entered of record during the time the lien of such tax lien or judgment was lost.

This act shall become effective immediately upon its final enactment.