50 Heller postage due stamp with dark bluish violet overprint "Karlovy Vary 1. X. 1938 ++ swastika", tied by first day postmark "X Karlovy Vary X / 1. X. 1938" on letter piece, issued only 640 examples - with first day postmark rare, photo expertize Brunel VP (2020) : "the condition is perfect. ", Michel 250.-