medals, including labor, materials, dies, use of machinery, and overhead expenses, and amounts received from the sale of such duplicates shall be deposited in the United States Mint Public Enterprise Fund. 4. Status of medals (a) National medal The gold medal struck under this Act is a national medal for purposes of chapter 51 of title 31, United States Code. (b) Numismatic items For purposes of section 5134 of title 31, United States Code, all medals struck under this Act shall be considered to be numismatic items.