Look at the pictures, it is a, beautiful high chrome model you would be proud to put on your bike. I am going to call it used, but there is no evidence it has been mounted, possibly New Old Stock, with slight corrosion at some of the welds.
It is clearly marked CB750K2. However a CB750 K2 was a 1972 model, and had a Honda Product Code of 341. Honda used that same model code (341)through 1976 which means the frame is essentially unchanged.
This may fit all CB750 1972-1976. However, check with me if yours is not a K2, and I can take measurements to assure a fit, as there is no return of product.