2(1)For purposes of the principal section a company which has at any time been an overseas trade corporation shall be treated as if it had never been an overseas trade corporation and, subject to sub-paragraph (2) below, as if it had been charged to income tax and profits tax, or corporation tax, and been given credit for foreign tax accordingly.
(2)Where a company is an overseas trade corporation in the year 1965-66, then—
(a)in respect of any amount taken into account by virtue of sub-paragraph (1) above as income in the base year there shall be treated as allowed credit for foreign tax equal to the income tax and profits tax treated by virtue of that sub-paragraph as charged in respect of it; and
(b)in arriving for any year of assessment at the adjusted aggregate amount in the related period of the unused credit for foreign tax, the unused credit for foreign tax in respect of the income from each overseas source of trading income shall be computed as if the foreign tax were 56J per cent.