[William]

That is #3 for sure. Notice the missing nut on the upper alt bracket stud.

It is highly likely that is #5 based on it being a dark color automatic and the mention that it went to Shay Nichols. Gibb sold the #2 car shortly after he received it.

The #5 test was reviewed 30 years later by the original writer, Ro McGonegal in the June 1998 Hot Rod. He mentioned the car was built with a "vacuum secondary" carb and they swapped an 850, making traction worse. DH managed an 11.64/122 out of it with lousy traction-it was cold, early in the year as Gibb is wearing a top coat and the trees in the background are bare.

I guess #5 still exists but there is not much left.