The Secretary of the Treasury be, and he is, authorized, when it appears to him to be in the interest of commerce, and notwithstanding any provision of law or regulation requiring that the transportation of imported merchandise be by a bonded common carrier, to permit such merchandise which has been entered and examined for customs purposes to be transported by bonded cartmen or bonded lightermen between the ports of New York, Newark, and Perth Amboy, which are all included in Customs Collection District Numbered 10 (New York): Provided, That this resolution shall not be construed to deprive any of the ports affected of its rights and privileges as a port of entry.