The provisions of an amendatory Act of 1955, which was approved June 30, 1955 and which was Senate Bill No. 328 of the Sixty-Ninth General Assembly and which amended certain provisions now contained in Section 11-13-4 through 11-13-8, shall not affect the validity of any variations approved by the corporate authorities or by the board of appeals and in force prior to July 1, 1955.
65 ILCS 5/11-13-9