1986 Gibson SG

Can someone confirm what model this is? It has no pick guard, 3 knobs and 1 switch...from what I can tell it's a "special". Trying to help a friend get rid of this as he's strapped for the cash but arent sure how to price it. He hasnt had much luck on craigslist at $500.

http://jacksonville.craigslist.org/msg/2865841542.html