Golde Top wind bar
Hi Bill, that is a question that Alan Tast, or "Fuz" Johnson might have to answer. I just looked at the VTCI Official Factory Specifications (OFS) for the Squarebird. They mention the wind bar in it, and say that there were reproductions made of it. Perhaps it is the reproductions that are rectangular instead of tubular. But they probably know if there was a change in the production of the bar later on in the production process. I think I have only seen pix of the round one.
When ya get a chance email me your VIN # and Data Plate information. With that information, I can check the Tbird Registry for you and tell you if a previous owner ever registered it.