9802.00.80—Articles, except goods of heading 9802.00.91 and goods imported under provisions of subchapter XIX of this chapter and goods imported under provisions of subchapter XX, assembled abroad in whole or in part of fabricated components, the product of the United States, which (a) were exported in condition ready for assembly without further fabrication, (b) have not lost their physical identity in such articles by change in form, shape or otherwise, and (c) have not been advanced in value or improved in condition abroad except by being assembled and except by operations incidental to the assembly process such as cleaning, lubricating and painting