After restoring two cars, you gain an appreciation of what to look for and it takes time hunt them down and can include a little invasive looking if you want to be sure of what you're buying for big bucks. Some others having done or having their car restored, have tons of photos of what was done to the car - a safer buy. I have over 200 pictures of my car over the term of resto. For unrestored or original cars, a keen inspection is necessary cuz how the hell do ya know what might have been done to the car over 40-50 years? Mostly all concerned about the body; I've passed on a couple cars I really liked having one too many questions and there's usually a pattern or history of where cars tend to deteriorate based on mfg and model.