I just picked up the game and doing my first run through at the time of this posting. The question that came up is the check condition for the replacement of customer cards. Are the cards replaced at the end of the current player's turn or at the end of the round. This came up because it's end of round condition, the following player after the first is limited in the choices of purchase. I have looked through the rulebook and unfortunately I am not seeing any end of round or end of turn check conditions.
It's actually quite clear in the English rules. Page 5 talks about activating the steward's office, taking the customer cards and "Then, bring the display next to the steward’s office up to 6 cards again by revealing the required number of cards from the face-down customer card stack."
Therefore, it's refilled right after the player's turn.