I can expand a little bit..
The designer of the body was a friend of mine and I have the original drawing and three of the original pictures. When he designed the body my friend was only 20 years old.
ECA was an american organization to monitor the funds of the Marshall plan in Europe.
The chassis was made by Bianchi, quite possibly Audax or Civis.
From the pictures in not obvious, but it was a rather large vehicle.
Thank you for the puzzle and for the point.
