Honestly, in about equal measure.
my paternal grandfather, who passed away a half dozen years before I came along, was a serious modeler who kept it simple.
1/48- 1/4" = 1' -0".
He mostly scratch built his stuff, started any number of small cottage industries- he was COO at one of the largest agricultural tool manufacterurs in the Midwest, and operated the trains on club layouts with hand laid track at proper gauge.
the beauty of that being able to quickly assemble anything using any available measuring sticks around, cadging from the architectural model people (back when those were made by hand), and easily scaling down precut conventional materials.
President of the NMRA and I have quite a bit of his stuff. Lots of fabric insulated wiring and flashlight bulbs.
I think ship model scaling is a bit of a black art. Well known subjects- straightforward. Stuff like this, hard to say. My understanding of the real thing is that it's a facade on a barge basically. The best ship scaling method IMO is the horizontal dimension between major deck fixtures, like masts or turrets. But of course that takes drawings to refer to.
Somewhere there probably was a reference used by the original mold makers, but it may have been a photo of a modern Zodiac tied up next to it. I guess my peeve( and I'm not a peevish person although I do enjoy Beethoven) is that it get marketed as a different model. That may not be the case here.