Map of the Walled City, from Shanghai Commercial Atlas (1947)
This map of the former Walled City of Shanghai was extracted from the Shanghai Commercial Atlas 上海市行号路图录 (1947), georectified and digitized by Virtual Shanghai.
Clicking on the image redirects to the Goodle Drive download of the full-res JPG (25 Mb), which I made from the QGIS file.
Example of the maximum resolution.
Source: https://www.virtualshanghai.net/Data/Tables?ID=216