Auction # 2423 ARGENTINA: Special auction for the end of the first semester!!

GREAT RARITY: GJ.360a, 1915 12c. Plowman on Italian paper with horiz honeycomb wmk, block of 4 with original "M.I." ovpt. with a second added "I". All the stamps are signed by Victor Kneitschel on back, the bottom stamps are MNH (+50%), and the vertical perforation is a little separated in the top stamps. Exceptional rarity, one of the 2 blocks in existence of this variety!