Take a close look at the jacks in the Steamboat Arabia picture and you'll see similar fine quill blades as the secondary blades on many of them. Also on a couple of the congress knives.
http://www.bladeforums.com/forums/showpost.php?p=6964231&postcount=1675
http://www.bladeforums.com/forums/showpost.php?p=6964231&postcount=1675