Guide of official mail sent to New York on 20/SE/1929, franked by GJ.93 x8 (20c. San Martín with M.A. overprint), apparently one stamp is missing at right, fine quality, rare! (Image)

GJ.657, block of 4 with VARIETY: overprint at top, extremely rare. With small stain spots on gum (if washed they will lose the gum, but will be of VF quality), very interesting! (Image)