Need help valuing a 1969 Z-28

[musclecar65]

I am looking at buying a 1969 Cortez Silver Z-28 that appears to check out as a real one and was discussed for a buyer on this site back in 2017. The paint is excellent as is the interior, and underside looks very good for original, drives great, everything works.  That said it has issues: engine is the correct 302/290 but date-coded 7 months prior to build; Edlebrock carb, headers, am/fm 8-track, Richmond 5-speed, BF Goodrich Radial T/As, no vinyl top.  Comes with original 4-speed Transmission and has factory tinted glass, power steering and D80 spoilers. I think the grill is the wrong color. VIN 124379N682183.  Any help with getting me in the ballpark would be greatly appreciated.