There is a long list of things I'd like to do at the Deutsche Nationalbibliothek this week. One of them is a small attempt to identify some of the Black Hole cars.
And I have my first victory. This is the Umba Kleinauto with a 770 cc 4,4/14 PS engine by the Umba Auto AG (Hamburg 23 Pappelallee 41-43). If Wendax doesn't publish the article, I'll scan it tomorrow