In the saga of pre-war German automakers, there are two exceptionally important companies who—despite their intense competition—were inexorably linked through a flux of remarkable designs, technological breakthroughs, and, also, personnel.

Though the intertwined stories of Horch and Mercedes-Benz are both far too involved to adequately cover here, suffice to say that from 1904 until 1940, these two marques rivaled each other on the race track ( for victories ), and in the poshest neighborhoods and fastest autobahns throughout continental Europe ( for prestige ).

Founded by former Benz production manager August Horch in 1904, his eponymous company was quickly the sole domestic competitor to the “three-pointed star” within the market of fine luxury and sports cars.

By 1910, Horch had reincorporated under the Audi name, and by 1932 had merged his brand with three others to found the “Auto Union” conglomerate.

The marquee range found in Horch catalogues of the late 1930s was based on t...