He was born in Cremona, Italy which at the time was under control of the Austrian Empire, and was in close contact with Giovanni Battista Ceruti, who was also apprenticed under Lorenzo Stiorini.
[1] It was in Mantua where Giovanni worked with the luthier Tommaso Balestrieri, and moved there after eagerly finishing his apprenticeship under Lorenzo Stiorini.
One auctioneer describes his work as "rather rough... the purfling is careless, the wood not particularly handsome", while another: "Very careful workmanship.
[2] From these two auctioneer descriptions, it appears that his work varies in quality, although it may be based on the year or on the city where he crafted the violins.
While this may be a bit harsher for criticism, it does make some good points that the other auctioneers failed to address about Giovanni's attributed violins.