Well I guess it's probably similar to what you paid for it. Although, considering there are so few for sale at the moment, only 1 240z and 6 260z's on Carsales, it may have gone up a bit.
As above, pending body condition, if it's good, I would be guessing 20k and up. The more photos you have of the body restoration will increase the value I think.
But, as the old saying goes, it's worth what someone is willing to pay for it.
Don't know if the wheels are dear to you but, I'm with Patch, the car would sell for more with another set of rims.
Good luck with the sale and with the new Bub.
Mick