Blood on the Snow, the companion book for Robin Laws' game Hillfolk, contains a series pitch called "Shanghai 1930", which is about pretty much what you would expect.
Despite being well done for the most part, whoever wrote it went off the rails in a couple of places and just started making up random stuff.
Here's a little in the way of unofficial errata:
p. 45 (replaces the first 3 paragraphs, up to "The Western interests...")
Western Characters
As part
of the humiliating settlement the Western Powers forced on China after
the Opium
Wars, Shanghai became a treaty port, where British citizens were permitted to
trade with anyone they chose and to rent land. The British were soon joined by
the Americans and other foreign nations in gaining similar privileges, and a
parcel of land outside the old city of Shanghai became the International
Settlement.
Chinese
law does not apply to any citizen of the following nations: Belgium, Brazil, Denmark, France, Great
Britain, Italy, Japan, Mexico, the Netherlands, Norway, Peru, Portugal, Spain,
Sweden, the United States. These foreign nationals are instead tried by
a consular court if they are accused of crimes under their home countries’
legal systems.They can also, of course, get done for breaching the Settlement's own bylaws.
To the south of the International Settlement is the
French Concession. Unlike the Settlement, this actually is sovereign French
soil, and French law applies to all within its boundaries.
p. 46 (replace whole paragraph on The Bund)
The Bund: The
western shore of the Whangpu is built up with European-style granite
skyscrapers. The name of this stretch of the
International Settlement comes from the Anglo-Indian word bund, meaning an embankment. It rhymes with “fund”.