5No increase or reduction in any sum specified in—
(a)section 33(1)(b) or (c) or 50(3) of the said Act of 1914 ; or
(b)section 18(4) of the [1944 c. 15.] Reinstatement in Civil Employment Act 1944,
shall affect any case where the date of the receiving order (or, in relation to the estate of a person dying insolvent, the date of his death) occurred before the coming into force of the increase or reduction.