After a Comprehensive Plan and an ordinance containing Land Subdivision Regulations have been adopted and a certified copy of the ordinance has been filed with the County Clerk, a plat or replat of a subdivision shall not be recorded by the City unless it has first been approved by the Planning Commission. The filing and recording of a plat involving the subdivision of lands covered by such Plan and Regulations shall be without legal effect unless approved by the Commission; provided, however, that failure to comply with this section shall not invalidate or affect title to any land within the area of such plat or replat; and provided further, that if such plat shall bear the signature of the Chairman and seal of the Commission, it shall be presumed to have been approved thereby. (4-24-72)