black oval datestamp on cover to Irwin's Station, Pennsylvania, originated with "The Central Overland California & Pikes Peak Express Company Leavenworth City, K.T. Oct 6" oval, entered the mails with 1857 3c Dull red tied by black grid, matching "Leavenworth City Kas Oct 13" datestamp, forwarded with October 19 Irwin's Mills backstamp to Mercersburg, manuscript "Due 3", stamp two small pieces replaced, very fine and attractive, one of just three reported examples of the COC&PPE Leavenworth City oval, a beautiful and rare cover
Marc Haas (R.A. Siegel Sale 561, 1980)