(2.1) Where, at the time of the registration of a custom adoption or at any time after that, there is in the office of the Registrar General a registration of the birth of the person adopted, the Registrar General, on production of evidence satisfactory to the Registrar General of the identity of the person, shall cause

(a) the substitution of a new registration of the birth that is in accordance with the facts contained in the certificate recognizing the custom adoption and that includes the names of the birth parents as set out in the original registration of birth; and

(b) the original registration to be withdrawn from the registration files.