3 Heller postal stamp with bright blue green hand stamp overprint "Karlovy Vary 1. X. 1938+swastika", variety "inverted overprint", cancelled "Karlovy Vary 1 4. X. 38 4 b" on letter piece, only a few pieces known, expertized Dr. Dub (double signature) and expertise Brunel VP (2021) : "the condition is perfect. With inverted overprint is the stamp rare. ", Michel 1.200.-