Okay. I'll have a go at this. It sounds like fun.

If Theseus is manning the ship, then on D3002, it would still be the ship of Theseus (though that's only my opinion, of course). Why? To me, it's symbolic, a bit like a place of worship. You can build a church, synagogue, or whatever else, stone by stone, and invite people to come and worship with you. Is that a place of worship? I would say so. But the place, or the physical structure isn't what makes it so special. It's the spirit behind it all. And where does this spirit come from? The people congregated there. The combination of each person that joins. The place of worship could be torn down stone by stone and yet, as long as people will come to do what they have been doing regardless, that will still be their place of worship. Back to Theseus. Sure, you could argue that either of the ships, maybe both, or perhaps neither of them, is the true Ship of Theseus. The old pieces of the ship are just that. Pieces. They create a shell. It's what is inside the shell that matters, to me. The empty space that can be filled. Who is following the spirit that Theseus had originally instilled? Would it still be Theseus and his crew? Then that would be the answer. If this other person, not having known Theseus, unwittingly takes up that same spirit, then both of them might arguably be called the Ship of Theseus, though I wouldn't think that, unless by some strong circumstance, this stranger would take up the same name. If he knew Theseus, he might create a nickname or something related as an homage. In short, I believe it is the spirit within that tells one the truth.