Electrical accessories for round boxes
The so-called "round box" was the earliest type of wall box in use in Italy, and was common in most of Continental Europe, where it's still in use today (with a few improvements). Items mounted to round boxes weren't held with any screws; instead, they had sharp metal "arms" on the side which then bit onto the sides of the box once the screws were tightnened.
Whilst other European countries improved on this design, adding screws and desiging larger ones that could hold multiple devices, these updated wall boxes were never used in Italy, at it instead switched to rectangular ones, derived from the American standard, in the late 60s-70s.
Early devices meant for wall boxes were often a more premium alternative to ones that mounted externally to the wall, which was at the time much more common, likely because it was easier to retrofit.
Compared to later models, whose styling was designed to be visible and look good inside a room, these early electrical accessories instead did the opposite, trying their best to be hidden from sight. As such, they were often made with a clear (glass, and later plastic) front piece, to be easier to conceal behind a wallpaper, with only the bare miniumum being visible.
Early glass power socket
Rating: unknown
This power socket is an excellent example of how these early ones used to work. It's made of various materials: the frame is made of metal, with a ceramic part on the back to hold the contacts. The front cover is glass and mouunted using two threaded bakelite rings, which screw onto the contacts of the socket.
Of course, the fact that the front cover is only held by those bakelite pieces, which can be unscreweed by hand, is quite dangerous, as once removed the live connections are revealed.
BTicino lever light switch
Rating: 6A 250V
This light switch shows pretty well how these glass devices used to be installed, as it still has a piece of wallpaper present behind the front glass cover plate. As with other early light switches of this type, it uses a mechanism similar to North American ones: the switch has a lever that sticks out which is then moved up or down, similarly to switches used in hobby electronics.
As with the socket shown earlier, installation is done by removing a bakelite ring on the front and removing the glass cover plate. The screw terminals are on the back. The device mounts to the wall box using the standard mechanism of having metal arms on the side push into the sides of the box.
Rotary light switch
Rating: unknown
This light switch is similar to the ceramic ones shown earlier, since it uses a knob that's rotated to turn the lights on or off. However, contrary to some other models, this one can be turned in either direction, as the knob itself is held to the device with a screw.
By the time wall boxes were used, switches of this style had definitely lost some of its popularity, and faded away completely after glass electrical accessories fell out of fashion.
BTicino glass doorbell
Rating: 6A 250V
Alongside sockets and light switches, devices like doorbells were also available in this style. Interestingly, a date code of 1952 is present on it.
Glass and bakelite light switch
Rating: 6A 250V
Unlike the other ones this light switch has a large bakelite piece on the front, which is where the screws are.
Interestingly, the mechanism and shape of the lever on this one is very similar to American-style light switches, even more so than the other ones shown in this page.
Three phase power socket
Rating: likely 15A 380V
According to the cardboard piece present on the front, this is a "three phase socket with earth", made by the company Saigir from Trieste.
As with the other devices shown before, this socket is installed by unscrewing the bakelite rings surrounding the contacts and removing the front cover, which in this case is made of acrylic, not glass. Wiring is done on the back, with the four terminals for the three phases and the earth connections.
Double light switch
Rating: 6A 250V
This double light switch is mounted similarly to the other ones, although the front cover plate for this one is sadly missing. It's not clear who build this one, although the large logos on the back suggest that it was a company from Trieste.
As with some of the other switches shown in this page, this uses a toggle style switch lever mechanism.