12(1)This paragraph shall have effect in determining the principal value (and, accordingly, the market value for the purposes of capital gains tax under section 26 of the [1965 c. 25.] Finance Act 1965) of any investment (in this paragraph referred to as a " specific investment ") which is included among the investments to which a claim relates.
(2)Subject to the following provisions of this paragraph, the principal value of a specific investment shall be its sale value.
(3)Subject to the following provisions of this paragraph, in a case where the calculation of the loss on sale of the investments to which a claim relates is affected by subsection (4) of the principal section—
(a)if the value on death of a specific investment exceeds its sale price, the principal value of that investment shall be the aggregate of its sale value and an amount equal to the relevant proportion of the difference between its sale price and its value on death ; and
(b)if the sale price of a specific investment exceeds its value on death, the principal value of the investment shall be its sale value less an amount equal to the relevant proportion of the difference between its value on death and its sale price.
(4)For the purposes of sub-paragraphs (2) and (3) above, the sale value of a specific investment in respect of which an amount has been paid in pursuance of a call, as mentioned in paragraph 9 above, shall be reduced by the amount so paid in respect of that investment.
(5)In a case where, by virtue of sub-paragraph (3) of paragraph 10 above, the value on death of the new holding, within the meaning of that paragraph, includes an amount equal to the consideration referred to in that sub-paragraph, the sale value of any specific investment comprised in the new holding shall be reduced, for the purposes of sub-paragraphs (2) and (3) above, by an amount which bears to that consideration the like proportion as the value on death of the specific investment sold bears to the value on death of the whole of the new holding.
(6)In sub-paragraph (3) above " sale price", in relation to a specific investment, means the price for which the investment was sold by the appropriate person or, if it is greater, the best consideration which could reasonably have been obtained for the specific investment at the time of the sale ; and paragraph 8 above shall apply for the purposes of this sub-paragraph as it applies for the purposes of subsection (2)(b) of the principal section.