GJ.99, 1889 1c. Vélez Sársfield WITH Globes watermark, very fine quality (Image)

GJ.110P, 1889 10c. Avellaneda, IMPERFORATE PAIR, MNH (+50%), superb! (Image)

GJ.141P, 1892 5c. Rivadavia, IMPERFORATE PAIR, MNH (+50%), excellent! (Image)

GJ.142A, 1892 yellow-green, COLOR ERROR, very fine quality! (Image)

GJ.143P, 1892 10c. Belgrano, IMPERFORATE PAIR, very fine quality! (Image)

GJ.152PH, 1892 ½c. Rivadavia perforation 12, vertical pair IMPERFORATE BETWEEN, very fine quality, rare! (Image)

GJ.258, with COMPOUND perforation: 3 sides 12 and one 11½ (right side), very fine quality, rare! (Image)

GJ.307PH, 1910 12c. Congress, vertical pair IMPERFORATE BETWEEN, very fine quality! (Image)

GJ.321b, block of 4 WITH AND WITHOUT WATERMARK, MNH (+50%), excellent, very scarce. (Image)

GJ.336b, 1911 50c. Plowman, pair WITH AND WITHOUT WATERMARK, tiny hinge mark, almost invisible (appears MNH), excellent, rare! (Image)

GJ.390, 1915 2c. Plowman on Italian paper with HORIZONTAL honeycomb and PERFORATION 13½, MNH (+50%), excellent quality, rare! (Image)

GJ.458CZ, 1918 1c. San Martín without watermark WITH LEFT LABEL, not yet catalogued (it will be included in the next edition of the GJ catalog), MNH (+50%), superb and rare! (Image)

GJ.498, with complete DOUBLE IMPRESSION variety, very notable, not yet catalogued (it will be listed as GJ.498a), VF quality! (Image)

GJ.541b, with variety WATERMARK printed INVERTED, very notable in the sheet margin, MNH (+50%), excellent! (Image)

GJ.541CD, pair + RIGHT LABEL, MNH (+50%), excellent quality! (Image)

GJ.564CD, 1923 2c. San Martín with period, WITH RIGHT LABEL, not yet catalogued, rare, MNH (+50%), excellent. In the next edition of the GJ catalog it will be listed as GJ.564CD with a value of $50 for stamps WITH hinge mark (Image)

GJ.594c, pair WITH AND WITHOUT PERIOD, MNH (+50%), excellent! (Image)

GJ.598c, pair WITH AND WITHOUT PERIOD, mint, VF quality! (Image)

GJ.600EHA, vertical pair with decorated GUTTER, very fine quality! (Image)

GJ.623H, 1926 5c. San Martín printed on DUTCH PAPER, MNH (+50%), excellent. Along normal example for comparison (on English paper) (Image)

UNUSUAL POSTAGE: GJ.743, 4c. Brown used ALONE to pay the rate of a cover containing commercial papers or printed matter, from B.Aires to Switzerland, very fine quality! (Image)

GJ.747CD, pair + right label, MNH (+30%), superb! (Image)

GJ.756b, 25c. Plowman, pair with variety SUN VIRTUALLY INVISIBLE, very fine quality! (Image)

GJ.830, 1939 5P. UPU Congress, HIGH VALUE OF THE SET + other values (total 7.82P.) franking an airmail cover sent from B.Aires to Switzerland, VF quality, this stamp is VERY RARE on cover! (Image)

GJ.914b, with "PESOI" variety (position 11), excellent! (Image)