How do you recognise a “proper” dormobile?

Well, two ways spring to mind, the first being the type of roof fitted. Martin Walter usually fitted a side hinged roof that took up about 3/4 of the length of the vehicles overall roof, as pictured in the image above. Martin Walter conversions usually featured two glass windows and two opening vents in the fibreglass roof section.

The second and rather less obvious way would be to look for an official Martin Walter metal plate riveted to the vehicle, as seen in the picture above.