Bill, it's interesting and certainly of historical value, but of minimal monetary value (less than $100?). Best to give it to some antique electronics person who wants to fiddle with it. Otherwise, you can list it for sale on eBay.
Nowdays, it's kind of like a CD player will be 40 years from now.
Here's info: http://www.deadmedia.org/notes/13/139.html
http://www.nostalgiaair.org/PagesByModel/495/M0024495.pdf