I happened to stumble over this amazing website FULL of letterheads from people and places all over the world. Here are a few I loved, see them all here.. http://www.letterheady.com
National Air Races 1935
Carl Van Vechten, author & photographer, 1942
Letterhead used by Disney Productions in 1968 to promote The Jungle Book.
Letterhead used by management of the Dodgers in 1957, just months before they relocated to the West Coast and became the Los Angeles Dodgers.
Walt Disney Productions, 1951
International Brotherhood of Magicians, 1930.
Butler Brothers, 1935
Novelist Stephen King’s personal letterhead from the early-80s.
The Flemish Art Co., NY, 1905
The United States Playing Card Company, 1902
The Eagle Rubber Company, 1938