GJ.3A, 1883 3c. GREEN, mint original gum, excellent quality, very rare, signed by Marcelo Loeb on back. (Image)

GJ.6, used, barely cancelled, excellent quality, signed by Kneitschel on back. (Image)

GJ.10, mint, very fine quality! (Image)

GJ.11, mint with original gum and tiny hinge mark (it appears to be MNH), signed by Victor Kneitschel on back, VF quality, very rare! (Image)

GJ.14b, block of 4 with DOUBLE overprint, one faint, VF and rare! (Image)

GJ.19, mint block of 4, 2 stamps MNH (+50%), very fine quality! (Image)

GJ.35, complete sheet of 50 printed on VERY THIN PAPER in light gray (extremely rare!!) + other 2 sheets of 50 (without the sheet margins) printed on THICK paper in the 2 shades of gray very different between them, a few stamps with minor defects, most are excellent, spectacular group! (Image)

GJ.73, 1918 12c. San Martín in block of 4, all WITH W.Bond watermark, MNH, excellent quality, very rare! (Image)

GJ.88a, 1925 1c. San Martín w/o period, with INVERTED M.A. overprint, MNH (+50%), superb! (Image)

GJ.104, 10c. San Martín typographed with M.A. overprint, complete sheet of 100 stamps, MNH, superb! (Image)

GJ.141, block of 8 with DIAGONAL OVERPRINT (in the right stamps it is much lower!), also the top left stamp with RETOUCH on "9 DE J", VF quality! (Image)

GJ.245, 1923 1c. San Martín with period, perf 13½x12½ and M.H. overprint, excellent quality, very rare, signed by Victor Kneitschel on back (Image)

GJ.299, 1918 5c. San Martín with SERRA BOND watermark and perf 13½x12½, MNH (+50%), in pair, one example without watermark, excellent quality, rare! (Image)

GJ.309, spectacul complete sheet of 200 stamps with VARIETY: Overprint shifted towards bottom-left (very notable in the top left part of the sheet). There are 2 stamps with partial double impression of the overprint (pos.4 and 183), and "M without period" (pos.108), MNH, very fine quality. Value of a normal sheet US$150 +50% (MNH), low start! (Image)

GJ.425EN, vertical GUTTER pair, VF! (Image)

GJ.427EN, vertical GUTTER pair, VF! (Image)

GJ.492a, pair WITH AND WITHOUT period after the value, excellent quality! (Image)

GJ.524, 1912 12c. Plowman perf 13½, fantastic block of 4 of excellent quality, the stamps below are MNH, rare! (Image)

GJ.555, mint with tiny hinge mark, excellent quality, rare, signed by Victor Kneitschel on back (Image)

GJ.719, large block of 8 with the watermark VERY SHIFTED UPWARDS, over the face value, excellent! (Image)

GJ.719, block of 8 with DIAGONAL OVERPRINT, rare, excellent quality! (Image)

GJ.719, block of 8 printed on TRANSPARENT PELURE PAPER, rare. We include a block of 4 on normal paper and another one on VERY THICK PAPER (very scarce), very fine quality! (Image)

GJ.736CA, 20c. Llama with Casa de Moneda wmk, WITH TOP LABEL, VF quality, rare! (Image)

GJ.736CA, 20c. Llama with Casa de Moneda wmk, block of 4 WITH TOP LABEL, VF quality, rare! (Image)

GJ.739, 1P. Sunflower, printed on soft imported unsurfaced paper, vertical downwards ovpt., COMPLETE SHEET of 100 stamps, MNH, perfect (catalog value US$900). There are repetitive varieties, for example: "spot at left of the overprint" (pos.24), "A of OFICIAL with accent" (pos.26), "bee above the leaf" (pos.82) and several examples with PARTIAL DOUBLE IMPRESSION of the ovpt., MNH, excellent quality, extremely rare. Very low start, good opportunity!! (Image)