GJ.11a, INVERTED overprint, mint without gum, VF! (Image)

GJ.213a, block of 4 with INVERTED overprint, excellent quality, rare! (Image)

GJ.371 + 371a, 1917 2c. San Martín with vertical honeycomb wmk and perf 13½, block of 4, one with variety "l without period", excellent quality, rare, signed by V.Kneitschel (Image)

GJ.667a, 2P. Fruit unwatermarked, strip of 3, the central stamp WITHOUT OVERPRINT (it only shows 2 letters, the rest is missing, the relief can be seen on back), excellent quality, extremely rare! (Image)