Württemberg, 1861, 18kr dark blue on thin paper. Nibbed perfs at top and right, tied by "Cannstatt, 6 Jan, 1864" cds with second strike alongside on cover to Chateau la Valliere, France, manuscript "Wf 12" accountancy credit, reverse with partial Paris transit and receiving cds's; cover missing backflap, Fine, still a rare 18kr single letter rate usage to France. Scott No. 29. Michel No. 20y; €5,000 for single on cover ($6,850)  Estimate $500 - 750. $0 (Image)