Welcome to the Shipbucket!
I have a feeling that there are some serious issues with this drawing.
Most important one is that it seems to be slightly mis-scaled: if the Wiki is correct and this ship is 67 meters long, then it should be 440 pixels long (440 x 0,1524 = 67,056) - and it is 448 pixels long (from tip of the bow to tip of the stern, without the flagpole). Next thing - there's an overhang/walkway above the lowest deck - it should be represented as being 3-pixel thick (contour-colour-contour), and the vertical supports should be also 3-pixel thick. The bridge deck seems too low (12 pixels - merely 1,8 meters) and details could be IMHO improved.
I don't know how accurate this drawing is, but I think it could offer some help: