64In relation to any time before 10th April 1966, section 252 of this Act shall have effect as if for references to the [1966 c. 4.] Mines (Working Facilities and Support) Act 1966 there were substituted references to the [1923 c. 20.] Mines (Working Facilities and Support) Act 1923 ; and accordingly regulations made before that date which are in force at the commencement of this Act under section 78 of the Act of 1947, shall have effect as if made under the said section 252 and as if, in relation to any time on or after the said 10th April, references in them to the said Act of 1923 were references to the corresponding provisions of the said Act of 1966.