We know that the Targaryens have two Valyrian Steel Blades. And asoiaf wiki entry on Valyrian Steel lists the two blades under those who have unknown fates. Is there any canon where we could at least infer what happened to those two blades? Specifically, when was the last time these blades were seen in the canon, worldbook?
EDIT: Also, do we have reason to believe that there would be a momentous event that at least one of them will be found and the one who wields it will play a big badass role in the fight agains the Others?