Canon Diablo, Ariz., May 8, 1893 (Yavapai), bold sharp cds and grid duplex (Meyer 2A, rarity 6) tying 2¢ red (natural s.e.) on illustrated hotel corner card to King of Prussia, Pa., receiving backstamp; light cover toning, still an Extremely Fine strike, one of three known examples of this postmark. Estimate  $150 - 200. $0 (Image)