Could the bustling street be Threadneedle st. Clue is, A gambling man may offrer odds of the entire road to a China orange (presumably Mandarin ) however, it is probably worth rather less than it once was. Thanks in advance, Colin
The street is Lombard Street. - all Lombard Street to a china orange - gambling on a (near) certainty - ie prepared to risk the whole wealth of the banking area of London against something worth a few pence