A charter-party executed in Saint Lucia may be stamped by the Director of Finance and Planning after execution upon the following terms—
(a) within 7 days after the first execution thereof, on payment of the duty and a penalty of $1.20;
(b) after 7 days but within one month after the first execution thereof, on payment of the duty and a penalty of $25,
and shall not in any other case be stamped after execution.