(1) Subject to subregulation (2), a contributor referred to in regulation 47 is entitled to receive, in addition to the pension payable under that regulation, an additional sum of:
(a) Two dollars per unit of pension for each complete year of service during the period that commenced on 1 July 1957 and ended on 30 June 1967; and
(b) Three dollars per unit of pension for each complete year of service during the period that commenced on 1 July 1967;
less an amount that is equivalent to four and three - quarters per centum for each complete year of service between the date of his retirement and the date on which he would reach the maximum age of retirement.
(2) An amount payable under subregulation (1) shall not be less than two - thirds of the amount that the contributor would have received if the amount to which he had been entitled under that subregulation had not been reduced in accordance with that subregulation.