Exemption from auxiliary duty on imported copper products where excess duty reflects toll processing and transport costs. Exemption from auxiliary duty on imported copper wire bars, cathodes and wire rods produced from concentrates sent out for toll smelting or processing, limited to the portion of duty exceeding the ad valorem ceiling where that excess represents toll smelting/processing costs (labour, materials excluding original goods, and other payable charges) and insurance and freight both ways, subject to import within one year and sufficient evidence of origin from the toll operation.