6. Any provisions of a structure plan, an old development plan (within the meaning of paragraph 2 of Schedule 7 to the Town and Country Planning Act 1971(1)), or a local plan adopted by a county or district council which apply immediately before 1st April 1988 to an area transferred by this Order shall continue to have effect in relation to that area as if they were part of such a plan made or adopted by the council of the county or district to which that area is transferred.