Upon extensive research, I found this
http://www.cozio.com/Instrument.aspx?id=5075
Cozio is a very reliable source and in fact,
Giovanni Gagliano was the maker of instruments labeled Joanes Gagliano and the labels also vary over the beginning of the 19th century, especially the spelling of Naples i.e. Neapol.
It is also important to view the work of his sons
http://www.kolstein.com/instruments/...83/index.shtml
The woods are of similar figure, overall bass outline is very close, one being flatback and the other round.
Another strong point is that the body is of figured wood and the original headstock is rather plain.
I am no expert on this matter but I do my research.