GJ.1, with the extremely rare FRANCA cancel of Concepción del Uruguay in red (+800%), excellent quality, with Alberto Solari certificate. NOTE: Until a few years ago, it was believed that this mark was of the city of La Paz (in Entre Ríos) until an entire letter was found that proved its true origin. (Image)

GJ.1, 5c. red, with FRANCA cancel in ogive of PARANÁ (+30%), very fine quality, signed by Alberto Solari on back (Image)

GJ.1, 5c. red, used with FRANCA cancel of Tucumán (+200%), excellent! (Image)

GJ.1d + 1e, pair of stamps with varities "double period after the 5" and "double period after CENTAV", used with very nice blue FRANCA cancel in ogive of PARANÁ (+30%), one example with small thin on back, very nice and rare, market value US$260, signed by Alberto Solari (Image)

GJ.3A, 15c. plate B, dark blue, ample margins, with cancel of Córdoba that I cannot guarantee is genuine (it appears to be, but I still have some doubts) and for that reason it is sold as mint (its catalog value is much lower than used: US$200 mint, US$500 used), minor thins on back, superb front, good opportunity! (Image)