Retrospective Customs and Tariff amendments expand refund, compounding, authority transfer, and machinery provisions across trade remedies. The Bill provides for import duty refunds where imported goods cleared for home consumption are later found defective or non conforming, subject to customs identification and export or relinquishment; authorises the Income tax Authority for Advance Ruling to exercise specified Customs Act functions with a customs qualified member and transfers pending customs proceedings; makes High Courts expressly capable of condoning delays in appeals and cross objections retrospectively; empowers rulemaking for compounding, export, destruction and refund procedures; extends Customs Act machinery provisions to safeguard, anti dumping and countervailing duties retrospectively; validates prior actions and clarifies textile blend classification by predominance.