Hello
Maybe some of you know the Blog "Indigenous Boats" aready. It is not about junks only but about all kinds of traditional boats.
There are some interesting books about junks and other boats from southeast asia for download. Some are in the JRA library some not: https://indigenousboats.blogspot.com/p/boats-of-china-and-southeast-asia.html
Anyway, the blog is worth having a look.
Alex