1923, Industry and Agriculture 1 r.-7 r., cpl. set imperforate, tied by cds. “MOSCOW 21 8 23” with additional RSFSR 10 r. Definitive to a registered envelope to Praha, no arrival as usual, minor soiling, still very fine. The convergence of a rare mixed franking RSFSR-USSR, possible only for a few months, and a very early use of the first commemorative set, certificate Leupold (2019)
