Looking at the model #4 and the first pic #20 you will see some kind of curved structure half way down the main cabin port and stb. really no idea what that is but someone must know. Having to look at the museum model more closely i can see some parts are missing but i could continue, however dilemma coming up when museum people say these models are accurate they must have something to compare it by i.e a drawing,painting,plan,photo and i've always thought there would be info out there so look what i found. This photo is the same TYPE of boat as the museum model smaller than it's sister the paddy boat but it clearly shows the structure for the oars or poles i think poles fwd of the main cabin as in the museum model so that resolves the walkway issue the dilemma now is do i continue with the model or try and make the real boat note it has done away with the bipolar mast but has same type of roof. When i think of river i just think river but water levels can go up or down maybe that is why some boats have oars and poles when the water level is low it might be to hard to row. Anyway will now have a deep think.