Exemption from additional duty preserved by amending prior customs notifications to clarify applicable basic duty rates. Amends multiple antecedent customs notifications to insert a saving phrase exempting specified goods 'from the whole of the additional duty leviable thereon under section 3 of the said Customs Tariff Act,' and, where stated, substitutes or prescribes the effective basic ad valorem duty applicable to those goods, thereby maintaining exemption from additional duty while clarifying applicable basic duty rates.