rag-shop

(bank): From the slang term rag (“a banknote”).

rag-shop (plural rag-shops)

1. (obsolete, slang) A bank (financial institution).
   • 1819, An Authentic Narrative of the Events of the Westminster Election, page 381:

     Downing-street must bow down before Threadneedle, and St Stephen's must crave licence of the Bank. We must not be surprised if the potent Senate of the Rag-shop should vote the Constitution void, and dismiss King, Lords, and Commons, as an expensive pageant, since they have taken our lives, properties, religion, welfare and morals, into their keeping […]

2. Used other than figuratively or idiomatically: see rag,‎ shop.

• John Camden Hotten (1873) The Slang Dictionary