Where in pursuance of subsection (2) of section 23 above a magistrates' court proceeds to the summary trial of an information, then, if the accused is summarily convicted of the offence—
(a)the court shall not have power to impose on him in respect of that offence imprisonment for more than three months or a fine greater than £500; and
(b)section 29 of the [1952 c. 55.] Magistrates' Courts Act 1952 (power of court to commit offender to Crown Court for sentence if of opinion that his character and antecedents are such that greater punishment should be inflicted than the convicting court has power to inflict) shall not apply as regards that offence.