50 Heller \"stamp exhibition, Pilsen\" with dark-rosa hand stamp overprint \"Karlovy Vary 1. X. 1938+swastika\", block of four, used \"Karlovy Vary 1 4. X. 38\" on letter piece, the stamp left at the bottom foxed tooth otherwise in perfect condition, issued only 615 examples - therefore are multiples rare, photo expertize Brunel VP (2021), Michel 320.- plus