And the link was to the first manufacturer of wonderboard in 1975. The point made is that this photo IS NOT a wonderboard core (sic) as you asserted.
![](http://algoxy.com/psych/images/southcorestands.gif)
I am explaining NOW, why YOU should think there was a concrete core, if you are sincere about seeking the truth, which is dubious.
I know the core was concrete.
The structure standing in the above photo can be nothing but concrete. Steel simply WILL NOT have that appearance.
Period, never ever, cannot be. Only steel reinforced cast concrete could withstand the crashing descent of hundreds of thousands of tons of steel. The appearance is perfect for the tubular cast concrete core.