These are the complete set of blocks. Top (purple) are blocks with an error perforated and imperforated - number. Below are the normal blocks (black), perforated and imperforated - number. Top right : S/S - ERROR!!!
Circulation 550 pieces - number, imperforated Mi. Circulation 1018 pieces - perforated Mi. The errors are in Years and numbers. Down below on the S/S is printing. Above on the S/S printing.
The "Mistakes" S/S are printing in violet colour. Below are the normal blocks (black).
Right : S/S, Circulation 12 000 - number, imperforated Mi. Block 174 II B; Sc. Left : S/S Circulation 180 000, perforated. Block 174 II A ; Sc. The item "Bulgaria 1987 Russia ERROR Space Achievements 1957 Bl.174 I+II, A+B MNH 4x S/S" is in sale since Saturday, July 18, 2020. This item is in the category "Stamps\Europe\Bulgaria". The seller is "valeri_t" and is located in Sofia. This item can be shipped worldwide.