It basically is going to tell you who the original selling dealer was and the original color. There is no other variation on a US car.
In the case of the '74's retitled by Ford as '73's, that may show if your car was originally sold in California and was built as a '74 model.
I'm not sure where Marti is getting all of his information from. I know that in the case of the '67 Shelby's, SAAC has supplied him with information, not Ford.
Some years ago I was talking to someone at a meet who said that their father worked for Ford and was responsible for the warranty claims on the Panteras. He said that information was kept on 3x5 index cards hand written. I should have kept his name and phone number. The significance of it didn't occur to me at the time.