Buyers and sellers of rare antique U.S. paper currency. They offer a selection of high grade large size type notes from 1862 through 1923 including legal tender notes, silver certificates, treasury notes, Federal Reserve notes and gold certificates.
http://www.rmcurrency.com/

A site for collectors of currency, paper money, stocks and bonds, and the hobbies of Syngraphy and scripophily. Database of coin values.
http://www.ronscurrency.com/

Extensive listing of banknotes for numismatic collectors and dealers. Banknotes and paper money from Afghanistan to Zimbabwe and other world rarities.
http://www.ruoho.com/