The salvamanubrio is exactly what the words mean: handlebar protect. It is a simple device that was mounted onto upright bars (and less often on drop bars)at the point where one would normally lean the bike up against the wall. Made out of a soft rubber, it would not only protect the chrome on the handlebars, but also prevent the bike from sliding and falling. It should be noted that apart from the occasional stand built into the rear carrier, Italy was very averse to BB mounted kick- stands, so either these handlebar protectors were used on their own or in conjunction with saddle clamp mounted pop-out stays. I have just such a stay on my 30's vintage Bianchi city bike.
The salvatubo is used on step-through frames to protect the finish of the frame when you are stepping through. It is basically a tube that fits over the frame tube.