AWA on ESPN Classic, etc.

How is it that ESPN Classic can show reruns of AWA without having to pay WWE any money?  I understand that it aired on their network, but if you use that theory the TNT and TBS can show reruns of Nitro and Thunder without Vince's permission?
Why hasn't ESPN Classic shown WCCW?

Because it's not a "theory"; ESPN signed a very specific deal with the AWA when they aired that show, basically giving them rights to show it in perpetuity because they were taking such a big risk by buying into the company and wanted some way to recoup their money.  I don't know of any other deal structured like that, actually, and TNT definitely can't show reruns of Nitro.