“ Except as otherwise provided by law, the knowing manufacture, reproduction, sale, or purchase for resale of the Seals or Coats of Arms of the President or the Vice President of the United States, or any likeness or substantial part thereof, shall be permitted only for the following uses:
(a) Use by the President or Vice President of the United States; (b) Use in encyclopedias, dictionaries, books, journals, pamphlets, periodicals, or magazines incident to a description or history of seals, coats of arms, heraldry, or the Presidency or Vice Presidency. ”