I've studied this prop a lot, there is a special weathering on the original model, the front of the Narcissus is weathered, while the back is clean because it was covered in the hangar bay, but I don't like this because it just looks bad, I want to make some nice light weathering and rised panels as an optional parts. As you wrote, there is a problem with the panels layout, because Pepakura will mix it a lot in the unfolding process, orthographic screens could be an option, but, isn't it amateurish? I should learn something about this.
But, I'm not worried, the Betty started as an pencil and paper model, and it is a decent model now, I hope it will make a justice here. Just, keep your fingers crossed!
P.S.: I've drew it 35cm long, I think it is big enough, but, there is no problem to print it bigger anyway, it is the good thing about paper model building, right?