Contex 10
Contex is a Danish firm, who made a bewildering variety of ten-key calculators, some hand-operated, some electric. They are not really four function calculators, but can, with some effort be used for multiplication and division. The only thing that is lacking is a counter register. The one I have, N° 434039458 is in splendid condition, has its cover, and the instructions are on a silkscreen plate under the machine. It is one of the first machines I acquired. I decided to do a quick series of photos while cleaning up, before it's going in a box in the attic... It's not very much use to try and write something about how it functions, as others have already done so with much more detail and even pictures.
The machine is completely local, having been bought in Antwerp. The store, nor the house it was in still exist. I do have the orignal manual in French, which you can find here.