Alpina
I have had 3 Alpina machines over the years, with varying paraphernalia. I sold the machines on, until I now have 2 left, of which one is still for sale - and of course a full set of paraphernalia, including the grey metal base, the box, the instruction manual and the leather carrying pouch. I elected to keep this machine, which has done its duty in a mathematical and natural sciences Gymnasium in Köln-Mülheim.Kaufbeuren, where the factory used to be both for the popular typewriters and for the calculating machines, is not photographed for Google Street View yet, but the factory still seems to be around - This is it, seen from straight on top.
For those who are wondering, the Alpina brand of BMW go-faster parts indeed does have a a relation with the office machinery. The latter factory was established by Dr. Burkard Bovensiepen in 1949, who sold it to the Vorwerk group in 1965. In 1962, he started building carburators for BMW 1500 cars, and on Jan. 1st 1965, incorporated ALPINA Burkard Bovensiepen AG, in Kaufbeuren, with 8 employees.
Some pictures of the calculator:
