The 1969 Z/28 is the most cloned car ever.
Be very carefull. Post the tag and the stamp pad for verification.
Look for single fuel line - holley cars had them.
Bracket for dual exhaust - only SS or Z cars had them.
Make sure the trim tag is not a "replica" - most important.
Check for original DZ stamping - easy to tell if you know what to look for.
Later cars have the vin by the oil filter.
Too much to learn in 5 minutes - post the pictures.
Also - no 69 Z's had A/C or Auto trans.
They all came with smog (Correct E-manifolds cost $1500)