(2)Any Customs-collector to whom such a requisition is directed shall proceed to levy such sum as if it were payable under this Act at the port at which he is the Customs-collector, and a certificate by the Customs-collector at the port at which the light-dues first became payable, stating the amount payable, shall be sufficient proof in any proceeding under section 13 or section 15 that such amount is payable.
