Hello
Searching around in the internet I found a name I had never heard of before. Etienne Sigaut was employed by a french company in China for several years between 1911 and 1947. He knew G.R.G.Worcester well and also realised that chinese junks will disappear soon. He made photos and sketchbooks that are in the Musée National de la Marine now.
The photos can be seen at: https://www.flickr.com/photos/musee_national_marine/albums/72157624086984226/
An impression of the sketchbooks are in the beautiful "Chasse Marée" No.283
https://www.chasse-maree.com/jonquessampans/
More, but in black and white: https://journals.openedition.org/tc/285
As the photos from flickr can not be downloaded and the pictures in the openedition are in black and white and not very clear I asked the Musée National de la Marine for PDF copies of the photos and the sketchbooks but wait for the answer.
Have a nice day
Alex