Mexico, 1868, 100c black on orange brown, Corrected Denomination, Guanajuato. Imperf, cons. 6-69, showing the characteristics of the 6c transfer type 6 and on paper similar to the paper normally used for the 6 centavos value, Guanajuato September town cancels (Schatzkes 477), ample to large margins, Very Fine, the unique discovery example of this corrected denomination variety, illustrated in Follansbee A Catalogue of the Stamps of Mexico 1856-1910; with 1997 MEPSI certificate. Scott No. 64 var.  Estimate $3,000 - 4,000. This variety was discovered by Doug Stout, which is an apparent error occurring in a 100 centavos stone when a 6 centavos transfer was entered and later corrected. $0 (Image)