I had a fascinating chat with Jimmy Woods at a show a two or three years ago, and he told me then that his models are built almost 100% from WOOD, he doesn't like working with plastic of any kind, and only uses it for some detail work. Unless he's changed his techniques recently, which seems unlikely, the hull of Polar Star will be an old fashioned plank on frame job, probably using 1.5mm ply planks on 3mm ply frames, and the superstructure is nearly all plywood too. The hull on the model we'd been discussing had that look of solidity and uniformity that you get with those old pre-WW2 shipyard models you see in museums, that were mostly shaped from solid pine planks, what some older modellers still remember as 'bread & butter' construction. He showed me photos of the hull being built, and it was clear that he doesn't have to use very much filler to build hulls that are as good as anything I've ever seen.