Got it from someone who was working at MIT's AI lab when these were being built. He had this one in storage ever since.
I wasn't using Lisp machines in the 80ties, a was just a small innocent little duck back then.
Looks pretty much the section mark to me. Paragraph is in the same row on front of 9. dag, ddag, circ, bullet, all in the same row. Very logically arranged. If it is not the section mark I eat a broom!
You must ask him to tell some stories from the good old times!
Does he remember when this keyboard has been made?
ps: I really must stop looking at these pictures. They make me wonder which of the top lables are in the repertoire of Signature Plastics and how much the front printing will cost ...