Thank you so much for the detailed information and the reference. I assume Senshi Sosho was published in Tokyo by the Japanese Military History Department - was there a lead author and when was this particular volume published.
I have a few more questions.
1. I presume the Shohatsus were transported by trucks to Johore. Do you know how they were handled once at/near the Skudai River. Were they hidden among the trees like the smaller collapsible boats? I wonder whether the Shohatsus could be carried by men through the trees and launched into the river like the other smaller boats.
2. Your list includes the Type 100 pontoon but no details of this vessel are provided on the website you kindly showed me. Can you provide any information about the Type 100 pontoon?