1879, 30¢ full black, earliest known usage. Large margins, tied by grid cancel on oversized registered cover to Basel, Switzerland paying the six times U.P.U. rate, purple "Registered, San Francisco, Cal., Aug 8, 1881" straight line date stamp, cover tear at bottom and stamp lifted for examination and placed back noting light crease at bottom, otherwise Very Fine, a wonderful high value Banknote EKU and one of two earliest known usages of the 30¢ American Banknote issue; with 1998 A.P.S. and 1997 P.F. certificates. Scott No. 190  Estimate $1,500 - 2,000. $0 (Image)