The name you informed was wrongly spelled !
It must be
Gaetano Guadagnini ( Born in Turino in 1750 passed away in 1830 )
Taurini fecit 17..
In the beginning of the 20th century, lots of German made violins had fake seals of this Italian master.
The only way to know whether your violin is origin or not is to have it tested on wood-rings (dentrochronology test )
If it is origin your violin is worth from 50 000 USD !!!