1(1)No first-year allowance shall be made in respect of so much of any expenditure as is taken into account for the purposes of—
(a)any grant towards that expenditure made under the [1966 c. 34.] Industrial Development Act 1966, or
(b)any grant towards that expenditure made under the [1966 c. 34 (N.I.).] Industrial Investment (General Assistance) Act (Northern Ireland) 1966 by virtue of the Industrial Investment Grant (Addition of Eligible Assets) Order (Northern Ireland) 1967, or
(c)any grant towards that expenditure made under the last mentioned Act and exceeding 20 per cent. of that expenditure, or
(d)any grant towards that expenditure made under any agreement under the [1966 c. 36 (N.I.).] Industries Development Act (Northern Ireland) 1966 made before 1st August 1971 other than one made after 16th February 1971 and providing that no grant payable thereunder in respect of expenditure on machinery or plant is to exceed 40 per cent. of the expenditure:
Provided that the Treasury may from time to time, by order made by statutory instrument, vary as respects expenditure incurred after the passing of this Act, or any description of such expenditure specified in the order, the percentages specified in paragraphs (c) and (d) above or either of them.
(2)If any such grant is made after the making of any such allowance, that allowance shall to that extent be withdrawn; and where the amount of any such grant is repaid in whole or in part by the grantee to the grantor, then, to the extent to which it has been so repaid, it shall be deemed never to have been made.
(3)All such assessments and adjustments of assessments shall be made as may be necessary to give effect to sub-paragraph (2) above ; and, notwithstanding anything in any other provision, the time within which such an assessment or adjustment may be made shall not expire before the expiry of three years from the end of the chargeable period in which the grant or, as the case may be, repayment is made.
(4)This paragraph does not apply to expenditure on the provision of ships.