At the moment, it is believed (1) this part is unique to Boeing 777s and (2) no other Boeing 777s are missing or lost a significant wing part
So, if someone can find a serial number that would be useful. Given the length of time and the complex interaction of currents and winds, while any confirmation is better than none, it is unlikely to help explain where the plane is or why it went there.
But, there are a few questions – is there any more debris in the float path? How was this missed by satellites? Does the damage (after 17 months in saltwater, storms, sun and so on) give any indications of what separated this piece from the wing?
There are quite a few barnacles visible – would they provide any clues?