The maker was Gamba flli (Gamaba Brothers) made in the city of Gardone, Italy. Yours was made sometime between 1946 when G. Gamba started production, and 1967, when G. Gamba sold his tooling to his brother, Renato.....and the company became Renato Gamba. These were reported to be well made high quality shotguns, but there are so few sales in the US that I cannot find comparable sales to give you a current value- sorry. You can get the best answer by taking your (unloaded) shotgun to a gun show near you, and let some of the dealers and collectors take a hands-on look at it. Condition will drive the value of most guns. There is not a high collector's market for these, but they are considered a quality firearm. Later model Gamba's are offered for sale for several thousand US $$$, depending on the model.