A certified person shall be deemed to be an authorised investment business firm under this Act: Provided that -
(a) any investment business services provided by that person are so provided, in an incidental manner and within the limits, conditions or constraints of the certificate granted by the approved professional body, and
(b) the certified person has never had an authorisation revoked under section 16 (2) of this Act and not re-instated and that no manager or officer or director of that person has ever been a manager, officer or director of an investment business firm which has had its authorisation revoked, under section 16 (2) of this Act and not reinstated.