This has always worked for me. Sometimes it is the simple things that works best. Also, crawl around with a flashlight and don't forget to look at the inside of body panels. They often tell the true story.
I remember seeing bodies for 330 2+2s lined up outside the shops that used their mechanicals components and chassis to build recreations of Ferrari's desirable two-seaters. I wonder how many of them have been returned to the pool of complete cars?
I see so many people get burned even buying in person. They really don't do their due diligence to investigate a car before they buy it.
It takes some effort but it pays in the end. Also never look alone. take a informed friend to help look over things with an independent eye. Never buy sight unseen. Contact a local expert or someone who can investigate the car for you before you buy. Or pay the plane ticket. a few hundreds can save thousands of dollars.
I bought a 65 Impala out of a storage unit with the expectation of getting a car with known and declared mechanical issues but with (i hoped) a largely intact body other than minor rust spots
What I got was a car with zero metal under the windshield (you could see into the dash when the windshield was removed), the expected set of matching missing floorpans (a previous owner had covered the rotted out floor pans with a mat of duct tape to hold the carpet up) and a street sign hidden in the rear quarter under a (no kidding) half inch of bondo
For what I paid for the car though, still no regrets although the body work has significantly extended the downtime before the car is eventually road-ready. I also found out to my surprise that the car spent much of its later life sitting and rotting in my front yard before it wound up in the storage unit. Every old car has a story or two in it.
Lets step back people and look at reality. Fact, those are Million dollar cars and the body work done on them was what was done, it may not be right, but you also don't know if it was all done at once or in stages over decades. I wasn't there when the paint was removed nor were you so there is no way to know the whole story. It isn't like you can just order up a new body panel for those cars so the shop did what they could with what they had.
With that pit of perspective, if several owners of historically significant cars worth about a million dollars couldn't get the work done right I will bet you some actual money that you are going to have to lower your standards or open a HELOC and crash your 401k to get a 1970 Chevelle into the all metal state that you believe it should be in.
Reality, it will cost $100,000 to restore a one off exotic to an all metal state it will also cost $100,000 to restore a 1965 Chevrolet station wagon to an all metal state. Fact both cars will have filler on them at the end of the job, cars leave the factory with filler it is reality.
Let he who has never just had the one thing that needed to be fixed taken care of without stripping the whole car to see if there was more damage cast the first stone. No one wants to open a can of worms.
Years ago I had an insured who was in an accident that caused some front end damage to a used Fiat that he had recently purchased. The car must have come from the East Coast because the undercarriage had a fresh and heavy coat of that black tar-like stuff that we never use on the West Coast. The shop hooked the car up to their frame machine and started pulling, and most of the front end of the car fell off. Turns out that the inner sheet metal on the car was rusted paper thin, which had been disguised by applying an extra heavy coat of undercoating.