I also saw the auction, contacted him and asked if he knew the part number and/or could send pictures of the box and label.
To his credit, I think he was utterly clueless; the box is just a plain white box with "Space-Saver // enhanced keyboard for IBM or compatible computers" written on it and the keyboard inside reminds me of a G80-1800.
I wonder what it would have gone for if it had been a real German Space Saver, though.
-huha