I believe Luffy is the incarnation of joy boy and the ship NOAH will be put to use on the command of Pirate King Luffy during the ends of One Piece and thus it will serve its Use.
But Franky wants his ship for the Pirate King..Luffy
The boat is for the mermaid princess. Only she can use it... with the power of sea kings
Personally I dont like the idea of Luffy being the reincarnation of anyone, simply because I like Luffy as himself, his own individual, one of a kind, the next pirate king... Instead of a incarnation of someone already within history.
What do you think?