GJ.24 + 24c, with normal + inverted overprint (the latter with thin on back) (Image)

GJ.30, 2c., with red overprint, very fresh gum (Image)

GJ.31, 4c. with red overprint (Image)

GJ.145, with vertical honeycomb wmk, block of 4, VF quality (Image)

GJ.170, with round sun wmk, block of 4 of VF quality (Image)

GJ.187e, with VARIETY: "M" without period (Image)

GJ.218a, with VARIETIES: "H" without period (pos.90) + almost invisible watermark (honeycomb), very interesting (Image)

UNCATALOGUED 3c. San Martín w/o period, M.H. ovpt., perf 13¼ x 12½, block of 4 with very fresh gum, extremely rare! (Image)

GJ.301, block of 4 with multiple suns wmk, VARIETY: left stamps with defective impression, minor staining (Image)

GJ.338, strip of 4 with uncatalogued VARIETY: DOUBLE overprint (bounce), VF quality and rare! (Image)

GJ.412h, with VARIETY: broken "M" (Image)

GJ.436, block of 4 with cancel of PUERTO PIRÁMIDES (Chubut), rare (Image)

GJ.443, $1 Map with borders, block of 4, one with VARIETY: First stroke of the "M" broken (Image)

GJ.482c, pair, one with VARIETY: first "M" incomplete (Image)

GJ.492a, pair with and without period, VF (Image)

UNCATALOGUED, 2c. San Martín with M.O.P. overprint, without watermark, perf 13¼ x 12½, rare! (Image)

GJ.571, MNH (Image)

GJ.649, corner block of 12, several examples with VARIETIES (marked with small arrows in pencil), catalog value of a normal block US$20+ (Image)

GJ.678b, block of 4, one with VARIETY: Isthmus of Panama without outline, VF (Image)

GJ.715, 2 blocks of 4 on Zarate national unsurfaced paper + white paper (Image)

UNCATALOGUED LABEL, Puma printed on national paper with top label, small thin on back, rare! (Image)

UNCATALOGUED, $2 Fruit on national paper, with overprint of Presidencia de la Nación, VF, rare! (Image)

UNCATALOGUED, 50c. Petroleum with straight rays wmk, with overprint of Presidencia de la Nación, VF, rare! (Image)