audidriver

I have the opportunity to buy a 1979 280ZXR with 56k original miles and have some questions. I'm not a Z car guy so I thought I would ask here. Car is all original and the interior is excellent. I know about the rail issues underneath but have not looked at them yet. For now let's assume they are ok. Car is in the midwest but never driven in winter. It Runs great and is mechanically solid. Chrome is all good. It needs a paint job however. Good news is the owner has an unused set of decals for it. (And don't ask, they are not for sale). My question is what's a car like this worth restored? And what is a fair price as is? Z prices seem to be all over the map. This one is rare for sure but not as desireable as others it seems. I would assume to maintain maximum value one would want to repaint in the original color and use the new decals. Although personally that's not the most attractive color combo and for my own use would prefer a different solid color, but would not want to diminish it's value. Any help here guys? Dan