Validation of assessments, etc. in certain cases

Notwithstanding anything contained as aforesaid, no assessment, reassessment, levy or collection of any tax made or purporting to have been made, and any action taken or thing done in relation to such assessment, reassessment, levy or collection, under the provisions of the principal Act before the commencement of this Act, shall be called in question merely on the ground that such assessment, reassessment, levy or collection was made by an officer who was not duly authorised to do so, or that the officer who made such assessment, reassessment, levy or collection had no jurisdiction, or that the procedure followed by him was not in accordance with law, and any such assessment, reassessment, levy or collection or any action taken or thing done shall be deemed to have been validly made, taken or done.