I have been trying to locate a picture of Barber Motors in Allendale SC, the dealership through which my GTO was ordered, sold and delivered. I have not been successful with my search, but I have located a picture of Palmetto Motors, which was the name of the dealership in the 50's. SC is known as the Palmetto State.
Barber Motors was located on U.S. 301, which was one of the main north-south highways of the day. In the 70's, Interstate 95 opened in that part of SC and took the vast majority of traffic off of U.S. 301. Many parts of U.S. 301 are practically deserted with many abandoned motels, restaurants and truck stops. Mr. Barber saw this coming and relocated his dealership to Columbia SC.
I am also posting a photo of what the former dealership building looked like last year.
If you have pictures of the dealership where your GTO was sold and delivered, please post it here!
Suggest you contact the local library in that area and see if they have any local info as libraries can sometimes produce local info by doing a little digging. You might also want to see if the town had a local paper as it may be available on microfilm and there may be some ads for that dealership advertising their cars.
Next suggestion is to find out if there is a local historical society as many communities have these. Often they can do a little research or get you in contact with someone who may be able to help.
Have used these type sources in my researching and they have sometimes proved to be very productive in providing materials I was searching for.