(1) So much of Chapters III and IV as relates to--
     (a) the nature of the suits cognizable by Courts of Small Causes,
         (b) the exclusion of the jurisdiction of other Courts in those suits,
         (c) the practice and procedure of Courts of Small Causes,
         (d) appeal from certain orders of those Courts and revision of cases decided by them, and
         (e) the finality of their decrees and orders subject to such appeal and revision as are provided by this Act,
     applies to Courts invested by or under any enactment for . the time being in force with the jurisdiction of a Court of Small Causes so far as regards the exercise of that jurisdiction by those Courts.
     (2) Nothing in sub-section (1) with respect to Courts invested with the jurisdiction of a Court of Small Causes applies to suits instituted or proceedings commenced in those Courts before the date on which they were invested with that jurisdiction.