seems to be still a mystery
It is a Lancia Aurelia B20 that belonged to a Brussels pharmacist who changed the drivetrain around 1960 after having difficulties with the delicate Lancia parts.
Why not Lancia? Well, simply because there are too many crucial differences. The front windscreen totally different in shape and is mounted in the body under a different angle. The Lancia windscreen stands much steeper.
The rear window is different in shape.
The closing gap between the door and front mudguard is different in line. The side windows are different. In the door the window of the Lancia is much longer, the quarter window of the Lancia is shorter.
Under the the bonnet the inner wings and bulkhead are totally different from the Lancia. The stucture of the bottom bodywork is also totally different.
The Mercedes has a chassis where the Lancia has a monocoque .
The shape of the boot lid is also different. The Lancia boot lid is rounder in shape and the bottom corners are different in line
The story that it was once owned by a Brussels pharmacist could be right. We have heard that story too.