Paragraph 5
Neither subsection (1) nor subsection (2) of section 112 of this Act shall have effect as respects—
(a)
the driving of a heavy goods vehicle of any class by a person who at the beginning of 2nd February 1970 was the holder of a licence granted under Part II of the 1960 c. 16.Road Traffic Act 1960 (other than a provisional licence) authorising him to drive a heavy goods vehicle of that class, or
(b)
the employment to drive a heavy goods vehicle of any class of a person who at the beginning of 2nd February 1970 was the holder of such a licence authorising him to drive a heavy goods vehicle of that class,
so long as (in cither case) the licence in question remains in force.