Courtesy of Joseph Daragon, Newman Portal has added a fixed price list from the Washington, DC dealer Ben. M. Douglas. This 1964 list included important examples of early American paper money, including seven Vermont notes and the always popular May 10, 1775 Continental $20, featuring a marbled edge. Douglas writes

Not surprisingly, the colonial paper money collector Eric P. Newman was not far behind, and his correspondence file lends additional context. Newman apparently traded with Douglas for some of the notes, and by mistake forwarded to Douglas an October 1, 1755 Pennsylvania one-shilling example, serial no. 6889. Newman reacquired the piece from Douglas, which later appeared in the Newman VI sale (Heritage Auctions, April 2015), lot 19530, and realized $1,527.50.

Martin Gengerke lists nine auction sales for Douglas, ranging from 1952 to 1956 and presented in the Numismatic Scrapbook Magazine. An additional six sales, 1957-1969, are listed for D&W Auctions, representing a partnership with the Baltimore dealer Thomas Warfield.

Link to Ben M. Douglas fixed price list on Newman Portal:https://nnp.wustl.edu/library/book/641478

Link to Newman / Douglas correspondence on Newman Portal:
https://nnp.wustl.edu/library/book/521678