] Tellson's. This was the bank in Dickens's `A Tale of Two Cities' which employed Mr Lorry.
Sir John Lambert was presumably the model for Dickens's Tellson's Bank, except for the name. Lambert was resident English banker in Paris for many years up to the French Revolution, and lots of English people would have had dealings with him, so he was widely known among the rich and famous British cosmopolitans.
Thomas Coutts was a more successful banker than Henry Austen: the bank is still going, and here's a link to their history on their web site. It's very boring, and misses out all sorts of interesting details, such as the fact that Thomas Coutts lent Charles James Fox a lot of money and hoped to recoup it when Fox took power in the Talents ministry. Presumably Henry Austen had the same idea when he bankrolled Moira.