Trademark on the back of a picture by <a href="//commons.wikimedia.org/wiki/Giorgio_Conrad" class="mw-redirect" title="Giorgio Conrad">Giorgio Conrad</a> (1827-1889) (Member of a fraternity. Catalogue # 221).
<a href="//commons.wikimedia.org/wiki/Giorgio_Conrad" class="mw-redirect" title="Giorgio Conrad">Giorgio Conrad</a> (1827-1889).
Self-scanned