I found my '68 GT/CS this past summer thru a listing on Craig's List here in So Cal. The seller didn't know anything about them and was supposedly selling it for his son who made an impulse buy from someone he knew that had it and seeing the son had a 1 yr old baby and was still a part time student he couldn't afford to restore it so dad said it had to go. It is a plain C code GT/CS that runs very well and is pretty much in original shape with the exception of aftermarket wheels, radio, antenna and steering wheel and still has the original paint although very worn and peeled all over most of the car. They were asking $10k but we came to agree on $7500 cash plus a new Dell laptop that I had bought 10 months earlier but never used and it had already been written off so didn't bother me giving it away like that. Keep your eyes open and keep searching ebay and CL as well as the classifieds and forum here and on VMF, you'll find one, just take your time, took me about 2 months.
Best of luck and let us know how your search progresses.
Happy Holidays all!