Soviet Union - Large Die Proofs

Soviet Union - Large Die Proofs
1983, 200th Anniversary of the Opera and Ballet Theater in Leningrad, two sunken die proofs of 4k stamp in black, complete or part of the engraved design, artist E. Egorov, size 100x120mm, first one with printer's markings at four sides, produced on gummed paper, traces of previous hinges, VF and very rare, Est. $800-$1,000, Scott #5142