I have one of those in 12 gauge 3" magnum. I think "Gardone" is the location in Italy where it was made, not the manufacturer, but I could be wrong. I have heard some were made by Beretta, don't know if that is true. I "think" they were made by more than one company.
It is an excellent gun, mine is in excellent condition. I cut my barrel down so that it doesn't stick out past the stock when folded. Also made the pocket in the fore-stock for the trigger guard deeper, so it folds more, or all the way in half. I use it for/as one of my trekking/exploring/map and compass/wilderness roaming guns, when I want the least amount of weight with the most power. Mine weighs five pounds. With 3" magnum slug loads, the recoil is beyond brutal, but I believe it will stop anything. For small game survival I carry a chamber insert that shoots 410 shot shells. I can carry a lot of those compared to 12 gauge shot shells.
Yes, those are neat guns and under appreciated. I like mine very much. I have never found much information on them. Also been told they were intended as skeet shooters.