Looking good Jeremy.
Can I make a plea, here. I know its your model, but I see from the mock-up that you are perpetuating an error that has bedevilled all I've seen so far, from the Hathaway card model to a 1:48 national prizewinner. That is, the crew heads, which are the prominent feature forward of the breastwork. These are invariably model as being similar, but slightly larger than those for the officers aft. This is, in fact not the case. The heads consist of a two-part structure - an open-air section, reached by climbing over a high ledge; and an enclosed part, where the WCs are. Hopefully the photo below will make this clear.
Early photos seem to indicate that the officers heads were also like this, but were later roofed over. The crew heads never were, as photos taken in the 20th century of the hulk under tow still show the open structure. It's a mystery to me why even the Webb plans show them closed in, as the plans from the Australian National Archive - if you study them closely enough - show the correct arrangement.
Good luck with your model.
Rick