(a) the tax that would be payable in respect of those goods if the goods were sold at their fair market value on that date; or
(b) the tax credit previously claimed in respect of those goods.
(2) Where the dealer has accounted for turnover on the basis of amounts received and amounts paid, he shall include in the turnover of his final return -
(a) any amount not yet received in respect of sales made while he was registered; and
(b) any amount not yet paid in respect of purchases made while he was registered.