ADDS MRD-700 keyboard
The photos below are archived from eBay listing 174835114088 “Cherry Computer Keys MRD-700 ADDS DATA Terminal Keyboard & Schematic/Manual” from seller graystoke, owner of store Good Stuff Sales LLC; the original listing has since been deleted by eBay.
The keyboard, Cherry model B80-22AA, is the keyboard from the ADDS Consul 880, Consul 880A and MRD-700 terminals. The Consul terminals are all-in-one units, while the MRD-700 has a separate monitor and keyboard. Based on the schematics shown, this seems to be from 1972 or later. (Identification of the all-in-one Consul terminals came from a Cherry magazine advertisement depicting the keyboard assembly.)
Although two members of the keyboard community were interested in the unit and decided who was to have it, the winning bidder was willing to pay a higher price, and the ownership is now a mystery; thus, the photos are archived here to prevent yet another loss of knowledge as unusual and rare keyboards from eBay disappear into unknown hands, never to be heard of or seen again. As such, the serial number remains unknown, as do all the manufacture dates of the ICs that would—together with the serial number—help to date the unit.
This model is notable for having the classic illumination kit. Curiously, these are fitted to alternate action switches, that one would assume would not need it. Thus, the slots in the side do not sit over the locating posts on the switches, as those were always absent from the M6 alternate action.