I had a chance to got to Brattle Book Shop this afternoon, and after searching through their outside book racks finally came across something that interested me enough to want to buy it.
According to several sources, The Silent Traveller in London was published in 1938, but this copy says "First published 1939." This copy wasn't in great shape, with some tears on the dust jacket that I'll have to fix, but it was only $5. The plates inside the book look good--nothing missing. (Someone else has helpfully posted scans of the plates.)
I found an interesting article about the author, Chiang Yee (蔣彞), that was published a few years back. There's another good article about Chiang here on the Victoria and Albert Museum's website.