GJ.637 + other values, 1928, 16 values of the first airmail issue, PROOFS in the issued colors on medium paper, some in pairs, all with punch holes, excellent quality, very rare! (Image)

GJ.1339, 1965 Stylized airplane 27.50P., block of 4 with VARIETY: Figure of the face value printed over the wing (airplane shifted to the right), excellent quality, rare! (Image)

GJ.1434, 1967 78P. Stylized airplane, corner block of 4 with VARIETY: Stamp in the corner partially unprinted due to pre-printing paper fold, and that area was printed partly on the sheet margin and partly on back, printed on gum, VF quality, very rare! (Image)