Here's what I have:
I'll post 4 pictures and the info I have on them, then my conclusions.
1) No picture: ISSI
Istittuto Scientifico Sperimentale Industriale, Milano
The ISSI, or Microbo, was a very light (350lb) 3-wheeler powered by a single cylinder 125cc 2-stroke engine. It had a two-seater coupe body with a transparent plexiglass roof.
2) No picture: ISSI
Istittuto Scientifico Sperimentale Industriale, Milano
The ISSI Microbo was an extremely short 86.6in (2200cm) but tall enclosed microcar. Unusual features included a single door on the right-hand side, integral construction and a transparent Plexiglass roof. A 125cc single-cylinder 2-stroke Idroflex 5.5bhp engine was mounted in the tail driving the single rear wheel.
3) no picture: CINGOLANI
Ezio Cingolani, Ancona
This minute but rather handsome 3-wheeled micro coupe used the mechanical elements of a Vespa scooter. That included a 125cc 3bhp single-cylinder engine and 3-speed gearbox. Its aluminium bodywork kept weight down to a mere 119kg, giving it exceptional economy. A production run did not ensue.
4) Picture n.1
Another midget auto at the Milan exhibit, a homemade runabout with the lines of a delivery truck, was powered by a one-cylinder motor-scooter engine. Ezio Cingolani, builder of the three-wheel Microbo, claims it has a top speed of around 40 miles per hour.
5) Picture n. 2 MICROBO
The 125cc Microbo (1952-1954) was an Italian design, but in 1953 it was advertised as being produced in France. it is unlikely that it was ever built in France and very few were made in Italy. This is the second-generation model, shown at the Turin moto show of 1953.
6) Picture n.3 CINGOLANI
Cingolani was an italian who took three years to build his own three-wheeled car. It was powered by a 125cc Vespa scooter-engine and at a reputed 119kg it was very light. In 1952 it received lots of attention from the press. Road tests proved it was a good design, but unfortunately it remained a one-off.
7) Picture n.3
ideal for a date, but not recommended for large families, is a junior limousine exhibited at the recent motorcycle show in Milan, Italy. The sleek three-wheel vehicle is designed to car-up to 200 pounds in addition to the driver. Built by ISSI Works, it is propelled at speeds up to 50 miles per hour by a one-cylinder engine.
Fact number 1 comes from "The new encyclopedia of Automobiles", n.2 and 3 from "the Beaulieu", n.4 and 7 from an issue of the same Magazine, n.5 and 6 from the same book about Microcars.
Here's the pictures: