My Great Aunt (95 years old) grew up in Zoppot and as a young girl (in 1933) had a 'Dauerkarte' (entry card) for the casino in Zappot. It is stamped 'Spielverbot!' as she was too young to be able to gamble.

Is there a market for such an item? What sort of value does it have? How would I or she go about selling it?