These studies have been going on since the creation of these violins. I read one where the violinists themselves couldn't tell the difference between a Stradiva

These studies have been going on since the creation of these violins. I read one where the violinists themselves couldn't tell the difference between a Stradivarius and a new high end model. I do wonder, pushing aside the fakes, how much of the original wood is in each Strad. After a few centuries, there had to be repairs, hardware updates, new coatings, and so on.