Sounds like a great find. Take some pictures for us when you get it home.

 

Be careful you know what you are looking at (or buying)
a 68 trim code tag will not tell you anything other than if the car was a v-8 or 6 cyl. (also tells where built and color codes)
It will not designate if the car is an ss.

A 68 SS car will have rectangular turn signals (grill), the domed
air intake style hood, rectangular mirrors, side marker lights @ at 4 corners.
All of these idents could be cloned (the marker lights would be the biggest amount of work)
A 68 SS could have a 10 bolt rear end. The front drums would also be finned on an SS.
If the car is an SS, it should be sold by now. (for $8K)
If the car is a cloned base car and is as nice as you describe
it is still a very good price for a straight clean 68.
If it is an SS, I would not wait until the weekend. Take some money to the guy now. It will be gone if anyone sees it who knows what it is. Best of luck!- JOLT

 

What jolt said.

Unless you have the protecto-plate and build sheet, there's really no way to tell if a 68 is a real SS or a clone.

However, if its as clean and rust free as you say it is, I'd pay $8000 even if it was a clone.

 

Ask the guy if he has any documentation to see if it's a real SS. Is it really "close to perfect" or good enough to be daily driven? There is a big difference as far as value.