Faith: I think you are on the right track in determining if the cars are the same or not. The boxed front horns may not be significant, as this was and is a common modification, but the dash support and steering wheel seems unique.

Even though various builders have added their own signature to the car over all these years and owners, some elements are usually retained. I don't know how detailed the pictures you have are, but some of the things you may want to look at are :

1) How the front end is set up. Look at the axle curvature on the ends where it was dropped. Also look at the shackles and perches, and how the shocks mount top and bottom.

2) How are the wishbones split, and do they mount in a similar fashion. Most remodeling jobs leave this area alone unless there is some problem that needs to be fixed.

3) See how the steering box mounts and the way the shaft goes into it. I forget if your car has vega style cross steering or traditional ford pickup style.

There should be a hundred little touches that are specific to your car and that would have probably remained even though other elements were changed over the years.

Don