The provisions of sections 66.060, 478.225, 482.325, 482.365, 506.010, 512.180, 517.011 to 517.151, 521.420, 535.020, 535.040, 535.110, 535.160 and 546.595 shall become effective January 1, 1987. Any case filed prior to January 1, 1987, in the divisions of the circuit court presided over by an associate circuit judge shall be governed by the practice and procedure of causes heard by associate circuit judges as were in effect on the date the case was filed, including the right to trial de novo.
§ 517.161, RSMo