Any member of the Capitol Police who by reason of the provision repealed by subsection (b) was receiving immediately prior to September 1, 1964, longevity compensation provided by section 105 of the Legislative Branch Appropriation Act, 1959, shall, on and after September 1, 1964, receive in lieu thereof a longevity increase under section
60j
(b) of this title, in addition to any other such increases (not to exceed three) to which he may otherwise be entitled under such section. In computing the length of service of such member for the purpose of such other increases, only service performed subsequent to the date on which he began receiving longevity compensation in accordance with such section
105 shall be counted.