The Cherry G80-0778 is a keyboard made by Cherry Corp.. The keyboard has been available as a regular product (see Cherry catalogues), as well as a rack mountable keyboard from a 3rd party manufacturer.
This particular sample is in German layout. It connects to both AT and XT and has got full n-key rollover.
The switches are Cherry MX Black which are the standard for industrial and POS keyboards. It is believed that this keyboard had been used with non-Unix computers, as it lacks several keys (mainly ~) which are required for Unix.
The blue plastic on the upper-left-hand side covers a hole in the metal cover. It had not yet been revealed why it is present. There is no LED underneath.
Rack mount version
Please see specification and model variants in the Cherry catalogue (File:G80-0777.pdf).