Saving provision preserves prior deduction treatment where pre amendment Supreme Court rulings differ from the new deduction rule. A saving provision preserves a taxpayer's prior deduction treatment where the Supreme Court, before introduction of the amending bill, on appeal or reference in respect of a particular assessment year, held that the earlier deduction method applied differently from the method introduced by the amendment; in that case the new deduction rule does not apply to the taxpayer for that specific assessment year determined by the Court.