For the purposes of section 11(b) and 27(2)(b) of the [1972 c. 41.] Finance Act 1972 (value of imported goods and of supply of goods in warehouse to include duty) the amount of any duty shall be taken to be the amount with any addition or deduction falling to be made under section 9 of the [1961 c. 36.] Finance Act 1961 (surcharges and rebates in respect of revenue duties).