Argentina, 1864, 10c blue, watermarked RA, clear impression, negative "OM" in oval bar cancel, margins large to just into frameline at bottom right, deep bold color, faint thin in watermark, otherwise F.-V.F., an attractive example of this key Rivadavia issue; with 1990 Holcombe certificate. SG No. 15. Scott No. 10  $6,750. $0 (Image)