gibson 12 strings

Value Of An Acoustic 12 String Gibson?
Ten years ago my dad found the guitar on a trash pile(it’s a long story involving a cheating husband and an angry wife with a shotgun). Daddy died a few years ago and mom wants to sell the “sordid thing”. But we don’t know the value of it. The headstock says “Gibson” and has two inlaid triangles. Those are the only markings. There is a triangular piece of metal under the bridge, the strings are attached to this. There are no numbers. It looks like the “Songwriter” model but the pickguard is not the same shape. My computer’s security system will not let me log onto the Gibson site. Anybody have any idea? Thanks.
Yahoo wanted to put this under fashion and accessories.
its hard to tell but Gibsons are nice!!!
If its in good condition, youll get a pretty penny for it.
Big Road Blues – 12 string guitar – Tommy Johnson