Way back in the sixties, there were camper conversions in the UK that were
cheaper than the Westfalia and were done in England.
One was Dorset and the other was Devon.   The Devon at least existed into the
70's
I owned a Devon conversion.    It was a splittie with the bigger rear window.
 1962 I think.
The roof was fibreglass and was hinged from one side and had 2 opening vents
in the roof.
The cabinets in the back were metal and housed a sink and stove which folded
out.
The rear seats would rotate and fold and could be made into 1 double bed or 2
singles.
A nice sized table folded up from the sidewall between the seats and could
also be hooked onto the back when the hatch was up.
There were also 2 fold out campbeds in the roof
It was a nice van but ......36HP!!
I remember having trouble passing 2CV cars in France.
My guess is what you saw was one of the British conversions, perhaps modified
later.
I seem to remember home made conversions as well.

Steve Cotsford
'84 Westy
Columbia SC