Can the locked motor be broken loose? Get the PB Blaster out and start soaking the cylinders. A big azz breaker bar on the harmonic balancer bolt might be able to get her spinning again and it could be salvageable. Sorry to hear of your misfortune. I guess I can see now why you didn't feel the mechanical survey was necessary. Hopefully the seller has a change of heart and offers some sort of compensation to make the deal right. Good luck.