The additional tax imposed by 26 U.S.C. 5001(a)(8), on imported spirits withdrawn from customs custody without payment of tax and later withdrawn from bonded premises for beverage purposes, and the related provisions of Sec. 19.257, are not applicable to Puerto Rican or Virgin Islands spirits brought into the United States and transferred to bonded premises under the provisions of this part. (26 U.S.C. 5201)