5 Die essays of designs similar to the adopted ones (3) or different (2), printed in black on yellow cardstock with values 5c, 10c, 54c and 1.80P (2 different), excellent quality, extremely rare group! (Image)

GJ.653, Photographic proof, full size, of an unadopted design proposed for the 1.80P. value of the first airmail issue, illustrator Godofredo Coca, VF and very attractive! (Image)

Circa 1935, die essay of unadopted design: "Airplane flying over the Andes mountains, view of Aconcagua", value 10c., engraved on paper affixed to card, excellent quality, extremely rare! (Image)

GJ.1357b, 1966 Navy aviation school (albatross), block of 4 with variety RED COLOR OMITTED (without the beak), MNH, excellent quality! (Image)