It seems that the piece of debris has more to it than just serial numbers. A german professor of the university of Cologne has identified goose barnacles on the pictures of the debris piece.
Goose Barnacle Wikipedia. He is quite certain that is a special kind of goose barnacle, Lepas Australis which lives normally in the waters west of Perth. In addition the goose barnacle only settles on pieces which are at least afloat in the sea for two months. Since there are quite a lot of them on the piece of debris it is highly unlikely that this piece of debris recently did fall in the water.
Here is the link to the article with a picture on which you can see the barnacles.
Kölner auf der Spur von MH370