(1) All entries for duty payment shall be lodged with the proper officer for checking and verification. Duty shall be collected at the rates fixed. An order according to Form C in the Schedule shall be issued for the delivery from the manufacturers' premises of any completed products on which duty has been paid.
(2) Where customs duty becomes payable on materials liable to duty ad valorem the highest value of the like materials imported by or for the use of the manufacturers during the preceding 6 months shall be taken for the purpose of assessing duty. However, the Comptroller may vary this basis where he or she is satisfied that such variation will not involve risk of loss of revenue.