Seeing that the auction states unrestored and the car has an X77 trim tag and the RS option was only on an X33 Z/28, I would question anything related to this car. Just look at all of the incorrect items for this "unrestored" car.
This car may have been purchased by the person on the sales invoice but as mentioned I highly doubt it was a Z/28 when they bought it.
People are getting pretty good at faking documents.
Big thumbs down.
Rick H.