The prohibitions contained in subsections (a), (b), and (c) of this section shall not apply with respect to any activity otherwise permitted by section
6004 of this title or section
6006 of this title or any activity which may not be regulated or prohibited under section 5(b)(4) of the Trading With the Enemy Act [
12 U.S.C.
95a
(4), 50 U.S.C. App. 5(b)(4)].