9. Where, apart from regulation 5(1) of these regulations, an officer who has purchased or is purchasing added years of contributing service under the principal regulations would be entitled to reckon additional contributing service to such extent that, if he continued in his employment, his total contributing service (including added years and additional contributing service) would fall to be limited under the said regulation 5(1) and regulation 28(1) of the principal regulations, the number of added years purchased shall be reduced by the number of whole years by which such total service would apart from the said regulations 5(1) and 28(1), exceed the limit specified in the said regulation 28(1), and the Secretary of State shall adjust the amount payable by the officer by way of lump sum or instalments accordingly.