(4)[ Notwithstanding anything in this section, the [State Government] [Inserted by A.O.1937.] may,until provision to the contrary is made by [Parliament] [Substituted by A.O.1950.], continue to levy anyduty which it was lawfully levying before the commencement of [the Constitution] [[Substituted by A.O.1950, for "Part III of the Governmentof India Act, 1935".]], under this section asthen in force:Provided that nothing in this sub-section authorizes the levy of any duty which as between timber or other forest-produce of the [State] [[Substituted byA.O.1950.]] and similar produce of the locality outside the [State] [[Substituted by A.O.1950.]] discriminates in favour of the former, or which, in the case of timber or other forest-produce of localities outside the [State] [[Substituted byA.O.1950.]], discriminates between timber or other forest-produce of one locality and similar timber or other forest-produce of another locality.]
