2. Except in so far as the Secretary of State may otherwise direct with respect to any particular case or class of case, in a case referred to in paragraph 1(b) of this Schedule where following—
(a)an appeal under section 6(2) of the Pensions Appeal Tribunals Act 1943 (appeal from Pensions Appeal Tribunal), or
(b)an order under section 6(2A) of that Act (joint application), or
(c)an order for a rehearing of an appeal made on directions given under rules made under paragraph 5 of the Schedule to that Act,
an appeal under section 3 or 4 of that Act has been reheard, the payment of a pension shall not be made in respect of any period preceding the date 6 years prior to the date (as the case may be) of the successful application for leave to appeal under section 6(2), the application under section 6(2A) which resulted in the order under that section, or the application for directions which resulted in the order for a rehearing.