1986 944 Automatic Transmission failure
 

I am looking at a 1986 944 with an automatic transmission. I know that they had a weak diff and were prone to breaking. But my question is this car still goes into park. If the diff broke wouldn't the car roll when in park. Is it possible that the driveshaft coupler is the issue? Had anyone run into this before? The fluid is clean and free of any metal. Foward and reverse are gone but park remains. I am trying to see how big of a mess I am getting myself into by buying this car and so I can make my offer accordingly.
Any help would be appriciated.
Thanks
Bob