Argentina, 1867, 5c rose red, thick paper, no watermark, believed to be from Kneitscel 6th printing (no. 27), without gum, ample to large margins, bright color, thin spot, otherwise Very Fine, Holcombe states "A very rare stamp, only a few copies of this stamp are known and this is believed to be the only unused copy."; with 1994 Holcombe certificate and letter concerning this rare issue. SG No. 21. Scott No. 15 var.  Estimate $1,500 - 2,000. $0 (Image)