If memory serves, back in the AEG Era, if someone had attached a Mayfair Family Deck and hexes to a dude, and that dude was hit by Unprepared, the hexes stuck around. Even if the Mayfair Family Deck was discarded mid-shootout after being Unprepared. (Example: Faithful Hound. These days, Disarm.)
Is this still the case?
Shootout: Choose a dude. Boot that dude and their attached cards. That dude gets –1 bullets and cannot use their abilities. Their attached cards lose all traits, abilities, and bullet bonuses.
Mayfair Family Deck:
This dude has Huckster 0. If this card leaves this dude, discard all Hexes from this dude.
Rulebook, p. 19:
Spells: All spells have restrictions on who can attach them. Only Hucksters can attach Hexes, only Blessed can attach Miracles, and only Shamans can attach Spirits. Attach the card to one of your unbooted dudes at a location you control (the dude must beable to attach that card). The card sticks with them. A dude can attach any number of spell cards.