Exchanging British Pounds in Chicago

I normally do all of my foreign exchanges at the Chase in the Loop on Dearborn. Today I learned that the chase in the loop only deals with paper money, however. They told me that Harlan J Berk at 31 N Clark exchanges coins. They do exchange almost any coin but it's at a severe discount due (66% of the current exchange rate) to the high cost of shipping the coins back. They exchanged the coins and the proprietor told me to "buy chocolate" in the future. It has a better "return."