Hi Chris as a personal opinion I don't think the car is worth 16k, 13-14k max given todays climate, but as everyone else said its worth whatever anyone is willing to pay for it. With regards to the pictures, it would be nice to see some up to date pics of the car as the ones you show are somewhat older, and whether Z boy gave you the pics or not, they still belong to him in as far as usage you should of asked permission first but he doesn't care so thats neither here nor there.
As far as running you into the ground, thats not what our intentions are, we are simply identifying that there is a person trying to make a few bucks from a previous purchase and some of us respect you for that, whether you will or not is a different question, Im just glad you are not living in a total unrealistic world and asking for 50k like some knob jockey tried to do.... ahem....
But personally 13k would be my max and thats at a real push, you could turn around and say I dont know the full works that has been done to the car, or never seen it in person, but I have, 80% of the work done to your car I was there in person. I know the history really well, and 13-14k max is the most its worth.
Good luck with the sale anyway.