50 Heller postal stamp with bright blue green hand stamp overprint "Karlovy Vary 1. X. 1938+swastika", actual should the overprint on of this stamp in dark rose result - it is a colour error, cancelled "Karlovy Vary 1 4. X. 38 4 b" on letter piece, expertized Dr. Dub (double signature) and expertise Brunel VP (2021) : "the condition is perfect. With overprint in the colour error is the stamp very rare. ", Michel used not listed!