What’s the exact process to identify a real 66 Formula S Barracuda?

I see on your paper that the 150 speedo could be ordered separately. Only one of mine had the décor package but all had the 150. A lot of what you see could be pre-production and were never produced. I'm not saying I know everything but just telling you my experiences, my friends memories (worked on the lines and the engineers that I use to speak with). Again I don't know everything just trying to help out. Old and still learning ever day!