(1)Where an order for conditional discharge has been made by a magistrates' court in the case of an offender under seventeen years of age in respect of an offence not being—
(a)a summary offence, or
(b)an offence which, in the case of an adult, could have been tried summarily with his consent under section 19 of the [1952 c. 55.] Magistrates' Courts Act 1952,
any powers exercisable by that or any other court in respect of the offender after he has attained the age of seventeen years under subsection (7), (8) or (9) of section 8 of this Act shall be those which would be exercisable if that offence were such an offence as is mentioned in paragraph (b) above and had been tried summarily with his consent under section 19.
(2)For the purposes of this section the age of an offender at a particular time shall be deemed to be or to have been that which appears to the court after considering any available evidence to be or to have been his age at that time.