Theorethically, yes.
But it might be a joined ownership with the actual builder and the operator, perhaps, there's more than one thing at play, there's a vessel desing, but also a livery and likeness of a company.. And it's not a few tenners, to buy a piece of paper and be done with it. There's an awful lot more to it I would think. Specially with 'unique' kinda specimens, that made historie in some way or form.
Even if companies do not use old designs anymore, they are normally not keen on selling them to just about anyone. You're better off obtaining a permission from them to use it for your project, I think.