(a) The following articles are permitted to be imported into the Virgin Islands free of excise taxes provided such articles are imported only for temporary use within the Virgin Islands and are used exclusively for the purposes set forth below and provided further that such articles are removed from the Virgin Islands within six months from the date of importation:
(b) The sixth-month period provided in subsection (a) of this section may be extended, upon application, for no more than one additional period of six months.
(c) Upon the sale or transfer of any article described in subsection (a) or upon the first use of such article for a purpose other than that described in subsection (a) or upon the expiration of the six-month period described in subsection (a) or the extension thereof, excise taxes at the lawful rate at the time of importation shall immediately become due and payable.