Mexico, 1871-83 "Sello Negro" Covers. 16 scarce late usage covers; with towns including San Luis Potosi (Schatzkes 1460 & 1463), Villa Nueva (1925), Amatlan (1769), Santa Ifigenia (1046) with additional unrecorded, Tuxtilla (1815AB), Penon Blanco (283A), Leon (503), unrecorded Ixtan, Papasquiaro, Chiautempam (1656) and others; clear full strikes throughout, few cover flaws, overall Very Fine. Estimate  $750 - 1,000. $0 (Image)