Book "Marcas postales del Uruguay 1716-2000", very good book by Héctor Volpe Piano, over 100 pages with illustrations of all the known postal markings, excellent! (Image)

COLONIA - Buenos Aires, circa 1800: Folded cover with COLONIA mark in redish black, excellent quality! (Image)

Entire letter dated 13/NO/1806, sent to Buenos Aires with straightline "COLONIA" along "1" rating in pen, excellent quality! (Image)

MAIL WITH POSTAGE DUES: 4 Covers used between 1903 and 1905, all with postage due stamps and/or marks, interesting lot for the specialist! IMPORTANT: Please view ALL the photos of the lot, because all the covers have been scanned (both sides) (Image)

3 Covers of 1928 with interesting cancels! (Image)

Cover sent by the Embassy of Argentina in Montevideo to Buenos Aires, without postage (with diplomatic franchise of UPAE), on back datestamps of Montevideo and arrival of 17/JA/1928, very fine quality! (Image)

31/MAY/1935 PANAGRA first flight between Montevideo and La Paz (Bolivia), cover of VF quality, with Bolivia military censor mark on back. (Image)

20/NO/1936 Montevideo - Salto, PLUNA first flight, cover of VF quality with arrival backstamp (Image)

29/DE/1936 Montevideo - Rivera, first flight of the regular airmail service, with special cachet and arrival backstamp, VF and rare! (Image)

29/DE/1936 Montevideo - Rivera, PLUNA first flight, cover of VF quality with arrival backstamp (Image)

2 Special flights to Artigas Antarctic station in 1987 and 1989, VF quality! (Image)