Blakes 7 Ore Carrier - what scale?

As i'm building the Ore Carrier, i'm thinking ahead not only the painting, but the weathering too.
Weathering of course is crucial to convey a sense of scale to a model and to stop it looking pristine and toy-like.
And i'm thinking something like an Ore Carrier would have a fair bit of weathering, dust/dirt etc wouldn't it?
But to guess how much to apply depends on the scale of the model.
So what's the scale of the Ore Carrier?
Watching "Star One", we get a brief glimpse of the ship as it collides with the Nova Queen.
And, eyeballing it, its almost the same length as the passenger ship.
So, how big is the Nova Queen?
A clue is the Captain of the ship stating "there's four thousand passengers on this ship."
To give me an idea of just what they means in terms of size of a vessel to accomodate so many people, i Google'd "largest cruise liners" and found that the Quantum Of The Seas can take 4,180 passengers and is 1,139 feet long.
Taking that as a guideline, and the Ore Carrier being slightly smaller, lets make the Ore Carrier 1,000 foot long.
Quite a size, and much bigger a ship than i'd have thought (unless its the same case as the notorious moment when a Pursuit Ship stops short of colliding with the supposed to be much bigger Liberator but they didn't have a smaller scale model of the ship, so it appears enormous).
My model, which is pretty much studio scale, measures 19 inches long, which makes it then a 1/632 scale model - so that means any weathering i do has got pretty tiny for a ship that huge.