KALINOWITZ, 10 Pfg dark red-orange, 15 Pfg grey-violet, 20 Pfg blue, 50 Pfg dark brown Plebiscite of 20 March 1821 on letter to Munich, single-circle KALINOWITZ (KR, GROSSSTREHLITZ) 20 3 21 (OS handbook No. 135.1, plebiscite-day cancellation), crystal-clear neat central strikes of rare cancel, envelope vertically folded at centre, otherwise good condition