I recently acquired this through my network of friends
who know I collect "old computer stuff". It's a 2400bps
4-wire leased line modem. Seems to have been manufactured
in 1984. It has a nice case and power supply, that I'll
use for other projects if no one wants it or can make a case
for its preservation. I also have the "Maintenance Information
and Parts Catalog" (First Edition) and a customer troubleshooting
guide.
I seem to recall that there are a couple of modem collectors
on the list. Email if interested.
Bill