I've been in the collision and resto business for decades, and fixed cars worse than this. They should have not sliced the a-pillar before yanking the car. If someone wants to fix it who cares? It is their T&M. Nobody is crying over cars rebuilt that are worth way more than a 69 Z. BS on a salvage title. Nearly every classic car out there has been rebuilt with repro body panels. If you want 100% original then go buy one that has never been hit, never had rust or rot or repainted in any way.
I'm doing a Z with original drivetrain except the tranny for someone. The car will receive a dashtop, firewall, floor and trunkpan, tailpanel, roof skin, one driprail, outer wheelhouses and two quarters. Some are NOS parts. According to some this car should be scrapped.