Attorney? Really? Lets examine this for what it really is. You had a good running slant six that, lets say you were pulling to do a V8 swap. What's it worth? What could you sell it for? Lots of people give them away. Not trying to be an ***, but suits are all about damage. Yes, there was damage. By the time you spend enough to maybe prove it was their fault, you could have either fixed the engine or gotten another one. That's the sad truth. They got you by the nads pretty much. It's an old car. It's an old engine. They got more money than you and have attorneys on hand to handle stuff like this all the time. Consider it lesson learned and never let anyone else change your oil again. Ever.