If any article entered under section
1752 of this title is still in customs custody, under such entry, at the expiration of 3 months after the closing date of the fair for which it was entered, such article shall thereupon be regarded as an article abandoned to the Government and shall be subject to sale or destruction of the article and disposition of the proceeds of sale in the manner provided for in sections
1491,
1492, and
1493 of this title. For purposes of this subsection, any duties or internal-revenue taxes on the article shall be computed on the basis of its condition and quantity at the time it becomes subject to sale.