16If a payment is made as required by section 58 of this Act in respect of a period—
(a)falling partly before and partly after 5th January 1964 ; or
(b)falling partly before and partly after the date of any change in the percentage mentioned in section 4(1)(c) of this Act taking effect under section 5(1)(b) thereof; or
(c)falling partly before and partly after the date of any change in the said percentage or the sums of money mentioned in the said section 4(1)(c), or of any change in the rates of contributions set out in Schedule 1 to this Act effected by or in pursuance of any Act passed after this Act,
and the amount of the payment is less than the full amount required, the Minister may allocate the payment as between the two parts of the period as he may think fit, and the said section 58 shall apply to the payment as if the two parts of the period were separate periods.