Louis,
I'll ask my mother again. The first one that you showed to me did look familiar. The model from 1975/76 can only be possible if it was sold already before that date. I know for sure that it is before 1975 because my neighbour (strange, there isn't a female version for this in English?) died in 1974 and she had it obviously before that time.
Now I come to think of it, I have never seen the washers that I knew in my youth anywhere else: not the Bico, not the Bauknecht, not the washer that my neighbours had...