This one can be solved just guessing. There are no obscure names but one (that is not totally obscure after all).
It's a Lambretta-powered Morelli-bodied car that was planned to be shown at the '54 Turin Motor Show.
We are looking at a car made by a chassis supplier for some big names. It was connected with several know makers (like Ermini, but also bigger and still active ones), and 2 of these will lead to some web pages where it's written that the chassis was made by him. Another big name was the one that was going to host this little car in his stand (but it didn't, I think).
For the point I still need:
builder's name,
model's name
3 of these big names involved (1 of them, beside Ermini, was already guessed but went unnoticed...)