Lot
2664 P
Mexico, Airmail, 1922, 50c yellow & black, trial color, "Muestra" overprint, unwatermarked wove paper, imperf., block of 4, o.g., h.r. at top, never hinged at bottom, full margins, Very Fine, only 50 are said to have been printed, this block is most likely unique. Scott No. C1TC Estimate $750 - 1,000.