Auction # 2136 ARGENTINA: Selection of good pieces of the Tumarkin collection (part I)

GJ.1692, 1975 Southern Pioneers, José Sobral, block of 8 with variety IRREGULAR PERFORATION, the heigth of the top stamps is normal, the stamps in the 2nd row WITHOUT printer imprint and shorter, the stamps in 3rd row with printer imprint at top, and the bottom stamps are taller and with double printer imprint (top and bottom)!