Porre didn't had a ferry to Medina, it was Truce.
And even if he saw Melchior. I don't think Melchior would have told him of the Masamune. Or better yet, he would lie saying he didn't knew of it's fate after the Ocean Palace incident. After all, he being from the original time line, knows that he has a finished Masamune, and that he fixed it.
But since Dalton doesn't, it will lead to an interesting situation.