18 pioneer stamp dealers of the 19th century.
Unknown; processed and uploaded by <a href="//commons.wikimedia.org/wiki/User:Michael_Romanov" title="User:Michael Romanov">Michael Romanov</a>
<a rel="nofollow" class="external text" href="http://nystamp.org/Intertwining%20Part%201%20Image%201.jpg">An old German book picture</a> from <a rel="nofollow" class="external text" href="http://nystamp.org/Intertwining%20Part%201.html">'The Intertwining of Philatelic and Social History'</a> by Calvet M. Hahn