shall be deemed not to have been, and not to be, invalid by reason only of the fact that such power, duty, and function was so conferred and imposed on and assigned to, any such document was submitted to, any such act or thing was done by, and any such proceedings were held or taken by or before, the Commissioner.

(2) Nothing in the provisions of sub-section (1) shall be deemed or construed to validate any relevant act or thing done by, or any relevant proceedings held or taken by or before, the Commissioner in the matter of any relevant document submitted to him, or in any other circumstances whatsoever, if, but only if, such act or thing, or such proceedings, was or were subsequently held by any court of competent jurisdiction to be invalid on the ground that any power, duty or function not having been validly conferred or imposed on, or assigned to, the Commissioner under the principal Act, the Commissioner had no jurisdiction to do such act or thing, or to hold or take such proceedings:

Provided, however, that nothing in the preceding provisions of this sub-section shall be deemed or construed to preclude or prevent any relevant act or thing being done by, and any relevant proceedings being held or taken by or before, as hereafter provided in this Act, the Commissioner de novo under the provisions of the principal Act as modified by this Act.

(3) Where any relevant act or thing done by, and any relevant proceedings held or taken by or before, the Commissioner prior to the appointed date in the matter of any relevant document is not validated by sub-section (1) by virtue of the operation of subsection (2), then, such document shall be deemed to be a relevant document submitted de novo to the Commissioner on that date, and accordingly any relevant act or thing may be done by, and any relevant proceedings may be held or taken by or before, the Commissioner de novo under the provisions of the principal Act as modified by this Act in the matter of such document.