Is this a real Z/28 and what is it worth?

[PhilM]

I bought a 69 Z with the original block about 3 years ago. It was a shell with a verified cowl tag/vin. No real rust. All I got with the deal was the shell, complete motor, JL8 brakes, subframe and a shell 12 bolt. I paid a little over 6k for it. Not sure if it was worth it or not. I was going to do a resto with it, but for now it sits in a storage unit. I knew this car since 84.

I think the only way to tell a real Z is by the vin and cowl tag. I would think there is some online resource to check it out. That was done for me before i bought it.