Mexico, 1868, Hidalgo (thin figures, imperf), 6c black on buff, set in issue colors (Heath & Stout refer to them as essays), with additional 100c without period (7 proofs), 6c with o.g., others no gum, all with full margins, Very Fine, a very scarce set of proofs. Scott Nos. 58P-64P  Estimate $200 - 300. $0 (Image)