Retrospective amendment of excise rules validates prior actions and bars suits while permitting recovery after assent. Amendment retrospectively modifies specified Central Excise Rules as listed in the Fourth Schedule, deems all actions taken under the amended rules during the retrospective period to have been valid and effective, bars suits and enforcement against the Central Government or Central Excise officers in respect of amounts under those rules, directs recovery of amounts deemed payable within a limited period after assent to the Finance Bill, and declares the Central Government to have had retrospective rule making power for this purpose while preventing criminal liability for acts not previously punishable.