5.—(1) Where the officer has received non-effective pay or excess remuneration in respect of any part of his war service then that part of his war service shall be excluded for the purpose of determining the amount of the war service contribution unless that officer
(a)makes an application to the Treasury in the prescribed form within six months of the date when he was first employed in the Civil Service of the State as mentioned in Regulation 3 hereof or of the date of the coming into force of these Regulations (whichever is the later) or within such further time as the Treasury, having regard to the circumstances of the case, may allow, and
(b)states in his application that he has refunded, or is willing to refund, any non-effective pay or excess remuneration in respect of any part of his war service which he desires to be taken into account for the purpose of Regulation 4 (2) hereof and that he surrenders his right to any further payment of such non-effective pay or excess remuneration, and
(c)authorises any consequent adjustment in the payment of non-effective pay or excess remuneration as from the date when it first became due.
(2) Where repayment of any sum falls to be made by instalments, the application shall not be effective until the Treasury is satisfied that repayment is complete. If repayment is not complete within two years of the date of the application, then the Treasury may declare the application to be void.