9(1)The following provisions (under which the consideration for a part disposal of an asset, instead of giving rise to a gain (or loss) accruing on the part disposal, goes to reduce the expenditure allowable in computing a gain accruing on a subsequent disposal of the asset), that is—
(a)paragraphs (b) and (c) of paragraph 13(1) of Schedule 6 to the [1965 c. 25.] Finance Act 1965,
(b)paragraph 3(2) of Schedule 7 to that Act (as extended by paragraph 8 of this Schedule), and
(c)paragraph 4 of this Schedule,
shall have effect subject to the provisions of this paragraph.
(2)None of those provisions shall apply if immediately before the part disposal there is no expenditure attributable to the asset under paragraphs (a) and (b) of paragraph 4(1) of Schedule 6 to the Finance Act 1965 (deductions allowable in computing a gain), or if the consideration for the part disposal exceeds that expenditure but, if there is any such expenditure and the recipient so elects.—
(a)the amount of the consideration for the part disposal shall be reduced by the amount of that expenditure, and
(b)none of that expenditure shall be allowable as a deduction in computing a gain accruing on the occasion of the part disposal or any subsequent occasion.