It depends on what you want. If it is strictly a show car that will be competing in car shows, then it needs to be completely original, right down to the factory imperfections and assembly line markings. But, with the technology available today, it is possible to seriously over restore a car. Not only can the fit and finish be improved, but so can the reliability, longevity and performance. If it was my car, that is the way I would want it, as perfect as possible. The one modern thing I would not want is clear coat paint. It is far less durable than non clearcoat, and cannot be brought back to life by buffing and polishing. Oh, and if it was originally a non electronic car, I would not want any kind of electronics on it. I really hate seeing vintage cars with EFI engines.