1899, "Seated Liberty" type, die proofs without value and with inscription "CORRESPONDENCIA OFICIAL" in 4 different colors, printed on card with glazed front, with printing number "528" at left of the stamp, excellent quality, extremely rare! (Image)

GJ.81a, 1923 2c. San Martín with period, block of 4 with INVERTED "M.A." overprint, very fine quality, very rare! (Image)

GJ.87a, 1923 20c. San Martín with period, perf 13½, INVERTED "M.A." overprint, only known used, very fine quality, rare, signed by Victor Kneitschel on back. (Image)

GJ.89CD, 2 examples WITH LABELS AT RIGHT, normal and inverted watermark, MNH (+50%), VF! (Image)

GJ.97a, 1926 12c. Post Centenary with DOUBLE "M.A." overprint, MNH (+50%), excellent quality, rare! (Image)

GJ.178a, 1923 1c. San Martín with period, INVERTED "M.G." overprint, very fine quality, rare! (Image)

GJ.193EH, GUTTER block of 8, MNH (+50%), very fine quality, very rare! (Image)

GJ.247b, 1923 5c. San Martín with period, INVERTED "M.H." overprint, only known used, very fine quality, rare, signed by Victor Kneitschel on back. (Image)

GJ.419b, INVERTED OVERPRINT variety, used, excellent quality, rare! (Image)

GJ.483a, 1923 5c. San Martín with period, INVERTED "M.M." overprint, only known used, very fine quality, rare! (Image)

GJ.664a, 50c. Petroleum well, without watermark, block of 4 with INVERTED OVERPRINT and also offset impression on back, MNH (+50%), excellent quality, rare! (Image)

GJ.684CZ, 15c. Güemes unwatermarked, block of 4 WITH LABELS AT LEFT (white and barely decorated), MNH (+50%), excellent! (Image)

RARE VARIETY ON COVER: GJ.755a, 20P. San Martín, strip of 3 with DOUBLE IMPRESSION OF THE STAMP franking a registered cover sent from B.Aires to Bahia Blanca, VF. These genuinely used varieties are very unusual! (Image)