17(1)This paragraph applies to any pattern of weighing equipment—
(a)the certificate of approval in respect of which was, or is deemed to have been, granted under section 12 of the 1963 Act and was in force immediately before 1st December 1980, and
(b)which provides for weighing to be made wholly or partly in grains, stones, quarters, hundredweights or tons,
including a pattern modified in accordance with an authorisation of the Secretary of State granted or deemed to have been granted under that section before 4th April 1979 and for the time being in force.
(2) Without prejudice to paragraph 14 above, every pattern of weighing equipment to which this paragraph applies shall continue to be deemed modified to the extent necessary to require equipment of that pattern—
(a)to weigh in pounds with scale intervals in the form 1y 10n, 2y 10n or 5y 10n pounds, the index n being a positive or negative whole number or zero, in substitution for stones, quarters, hundredweights or tons or fractions thereof and to have its capacity expressed in pounds, or
(b)to weigh in multiples or fractions of an ounce troy in substitution for grains or fractions thereof and to have its capacity expressed in ounces troy.