That's what it boils down to, you are restoring a car to what the judges will be looking for. And unless there is a published judging standards guide, you won't know for sure what the judge is looking for until your car gets judged and you get to review what you got dinged for on the judging sheet.
Saddest part is that the judges aren't always right, and even a judging guide, if published, may not be 100% correct, so you may have to do something incorrectly in order to "win"!