I'm awaiting the outcome of this. I didn't even know about this until this thread. But my opinion of the condition of the car? Well....it'* been down there for 50 years. It'* bound to have some rust, but I really dont think it will be all that bad.
It doesn't look like it was completely wrapped in the plastic, just looks covered, in which case the plastic did nothing to protect it. I don't think it will be that bad though. It'* not like the water would eat away the paint to rust what was underneath IMO.