Mexico, 1863-64 "Sello Negro" Covers. 19 covers, usages during the early days of Emperor Maximilian; with towns including San Luis Potosi (Schatzkes 1443), Carro (1859), manuscript Morelos, Chacaltianguis (1776), Nazas (274), unrecorded "Franco En Tuxtla", Viezca (1432, 1432A), Celaya (1293), San Luis Potosi monogram (1454), Uruapan (948), Villa Nueva (1925), Matamoros, Catorce and others; clear full strikes throughout, few cover flaws, overall Very Fine. Estimate  $750 - 1,000. $0 (Image)