This may be a long shot, but, about 3 or 4 years ago, I remember a dark green, unrestored 2 dr third gen. Nova that came to our cruise occasionally. Our cruise was in Westfield, MA (I've since moved to Myrtle Beach). I think it was a 4 spd, 350 as well. I believe the owner was a used car dealer from either Western MA or CT. You can contact Gary Francis, who operates the Westfield Cruisers, where he may have some info on that car, because he knew the owner.
I can't remember Gary's phone number, but if you talk to him, you can tell him that you had talked to me (Bill Belisle).
Like I mentioned, it may be a long shot, but worth the try. Good luck.