The Caproni CB - pocket submarine - was used by the Italian Navy during World War II.
The model is scratchbuilt with resin and photo-etched parts.
It comes in 1/87 scale -HO model train scale.
The well car carrying the submarine (that one you see in the photo isn't the right one) will be reproduced (always in scratch built) according to the photos and documents I have.
Guns and bearings are turned from brass