[Upper deck, midship , port, under boat deck. ]
(1) Coaling hatch on boat deck
(2) Upper deck , midship. The plate on the deck seems to be a protection from bags of coal falling through the coaling hatch(1) .
Drawing (1) and (2) are from "PLANS OF SHIPS OF THE IMPERIAL JAPANESE NAVY - HISTORY OF SHIPBUILDING IN SHOWA ERA"(published in 1975) . It was only one of commerce in fine size in Japan. Unfortunately, the drawing is not clear. But recently EAGLEMOSS distributed clear drawings.
So I can see almost characters on the drawings now.