(a) When requested by the Postal Service, the Public Printer shall print, as a public document for sale by the Superintendent of Documents, illustrations in black and white or in color of postage stamps of the United States, together with such descriptive, historical, and philatelic information with regard to the stamps as the Postal Service deems suitable. (b) Notwithstanding the provisions of section 505 of title 44, stereotype or electrotype plates, or duplicates thereof, used in the publications authorized to be printed by this section may not be sold or otherwise disposed of.