Here is what I see someone advertising on eBay:
In the spirit of token sets, Mayday Games has created a special collection of tokens and card sleeves just for The Harbour (Le Havre)! It includes 110 standard clear card sleeves (59 MM x 91 MM card sized), just the rare size that you needed, and 5 people tokens to replace your discs.
But that was for 110 sleeves, not 20.
My set actually came with more cards - the standard 110 plus the 30-odd more for Le Grand Hameau.