There are (at least some) relations to Riteman+ plus printers:
* The DMP2000 accepts Riteman robbon ribbon cassettes
* The shape of the case of DMP2xxx/DMP3xxxx series does resemble the Riteman models (although it isn't identical; the front of the Ritemans has a short horizontal edge, then followed by what looks like as a steeper diagonal edge - look at the photos ot see for yourself)
* Unknown if the Riteman's internal PCB, mechanics, and Firmware do have relations to Amstrad models.