I worked for Nixdorf Computer for 10 years and sold some of the first 8870s in the US. The first machines sold here were US assembled from purchased components (DCC CPU, Disk, IRIS O/S, etc.). The were too slow for more than 2 or 3 terminals
Nixdorf Computer AG then began manufacturing them in-house in Germany and eventually phased out the US Assembly line in Schaumburg, IL. I also sold the first COMET system (s/w) that was sold as an alternative to NIDAS (original bill, post and inventory package sold to small businesses).
Nixdorf acquired ENTREX (key to disk) about 1977 which led to the 8850 line (Extrex made the 280, 380, 480 and 600 series Data Entry systems). US HQ was moved to Burlington, MA (and later Waltham). Nixdorf added the 8890 (plug compatible mainframe); tried WP for a short time - 8840, Communications boxes - 8860 (competed with IBM 8100) and even PC's -- 8810 --- none were really successful.
It was a fun company to work for, but they never had stable US Management which led to their demise.