http://tarisio.com/wp/2011/04/turin-violin-by-giovanni-battista-guadagnini-c-1771/

A FINE ITALIAN VIOLIN BY GIOVANNI BATTISTA GUADAGNINI, TURIN, c. 1771

Labeled, “Joannes Baptifta Guadagnini, Cremonenfis fecit Taurini, 1775.”
LOB 35.4 cm
* Sold with a certificate from Dmitry Gindin, London and with a dendrochronological report from John Topham, Surrey, dating the youngest tree ring to 1764. Estimate: $550,000–800,000