27E+WAny area to which sections 27 to 34 of the 1949 Act (the survey provisions) do not apply immediately before 1st April 1974 by virtue of the fact that it is or forms part of an existing county borough shall on and after that date continue to be excluded from the operation of those sections except so far as they are adopted under section 35(2) of that Act as respects the whole or part of that area.