How are guys matching factory paint ?

I would befriend an old body guy and ask what they did when the cars were 10y/o. Honestly, trying to match a single stage metallic with a base/clear or even the original PPG SS is going to be tough. I would take a sample of what you want to match, bring it to the store and isolate the new medium to the body lines and try to blend. I tried to match a 71 F7 sherwood green and it was wayyyy dark. I tried to do door and fender, but ended up having to from body line down. Both drivers doors and quarter. Better off trying to match what it is now or do a perspective point