(1) This Act, save as otherwise provided by it, shall, as regards offences under any of its provisions, have effect only in relation to offences wholly or partly committed on or after the commencement of any such provision.

(2) No repeal or amendment by this Act of any enactment relating to procedure or evidence or to the jurisdiction or powers of any court or to the effect of a conviction shall affect the operation of the enactment in relation to offences committed before the commencement of this Act or to proceedings for any such offence.

(3) If -

(a) a person is charged in the alternative with having committed an offence under a statute or rule of law in force immediately before the commencement of this Act and an offence under this Act, and

(b) it is proved that the person did acts which would constitute either of the offences charged, but it is not proved whether those acts were done before or after such commencement,

the person may be convicted of the first-mentioned offence but shall not be liable to a penalty greater than the lesser of the maximum penalties provided for the two offences with which the person was charged.

(4) Except as regards offences committed before the commencement of this Act and except where the context otherwise requires -

(a) references in any enactment passed before this Act to an offence abolished by this Act shall, subject to any express amendment or repeal made by this Act, have effect as references to the corresponding offence under this Act, and