This one was for sale for a long time a few years ago. I spoke to the original owner back in 2015 but decided against making the long trip to Wisconsin.
Here is the link from NastyZ
https://nastyz28.com/threads/original-1973-z-28.283198/
This appears to be a very nice car but was overpriced back in 2014, and is very overpriced today, IMO