As per case facts, Easland Combines cleared goods with approved classification lists, availing an excise duty exemption. Later, a show-cause notice was issued for differential duty, alleging misstatement because a ... branch factory wasn't registered as an SSI unit, though the main unit was. The Tribunal initially found willful suppression, invoking the extended limitation period. The question arose whether retrospective amendments to Section 11A of the Central Excise Act, 1944, affect the sustainability of demand when clearances were made against approved classification lists, potentially overriding previous judgments. Finally, the Supreme Court ruled that the retrospective amendment to Section 11A fundamentally changes the legal basis, validating duty demands even if based on previously approved classifications, making the Cotspun judgment irrelevant. The Court set aside the finding of willful suppression but remitted the matters to the Tribunal for re-determination under the amended law.