DISRAELI GEARS
Itallia appears to be the derailleur brand of a company called Etablissements Itallia, based in Dole in Eastern France.
As far as I can see, the 'Itallia' name derives from the fact that this is a French device that is a fork model, activated by a long lever and rods, much like the Italian Vittoria designs of the time.
Le derailleur Itallia 1939?
Le derailleur Itallia 1939?