I was looking at my file of pictures that I have of my car throughout the years. I see one of those antenna balls on it on about a dozen of the pictures throughout the 70's. Some of them were the Union 76 orange and some were blue/green. I think the blue were a local Sinclair distributor called Village Pump.
That Colorado canyon shot in the '73 picture below has a ball on the antenna in the higher quality original file.
