We have an antique Antonio Stratavarius which we are seeking more information about?

The violin was passed down to us from his mother from a great-great uncle. It has a label inside, which is difficult to read. It was repaired in Boston, Massachussetts in 1868 by A. J. White. All signatures and dates were hand written. With all the hype about knock offs, and reproductions, it has left us wondering more about its value. We do know that it is at least 150 years old. Please help.