Recently purchased a copy of Artur Leonel Barbosa Carmona's books "Lorchas, Juncos, e Outros Barcos Usados No Sul Da China" which as the title implies is written in Portuguese. If there is an English version of the text I have found no evidence of it's existence.
The book is a fairly short work, richly illustrated, focused on craft of the Zhujiang/Chu Kiang delta and South China Sea. As far as I can tell, there is little overlap with Worcester or Audemard or other major works on the topic. I have no Portuguese or Iberian language skills, but the google-translate app has a helpful photo translate tool that I have been using to read the sections of the book which interest me most.
The section below was particularly interesting, as I have never seen a vessel resembling the one in the illustration.
"The 'Tou' is a generic designation of row boats. The largest has 75 cubits in length, 20 in the mouth [beam] and 5 to 6 in draft...forming a large deck, with two floors and accommodation for passengers and cargo holds...They run routes for these ports in the East River Delta. Today these "tous' are already in tow by steamboats, costing $9,000 and $10,000"
I have been looking for additional information about these sorts of vessels, the picture aligns with some of the information I have seen passenger boats towed by steam launches. The top level of decking seems to be the sort of rough mat awning under which the cheapest class of far sheltered on overnight journeys. The front half of the vessel resembles photographs and descriptions of other towed passenger vessels, but the rear half of the vessel is more like the stern of a mayangzi or the larger class of Hua Ting.
All in all, an interesting source which has presented many new lines of inquiry to pursue.
