rotted torsion bar cross member

If you havn't done this already. You need to inspect the complete bottom of the car. I have found that when one part of the unibody/frame is that rusty that other parts such as the front or rear frame rails are in bad shape also. Make sure the car is worth repairing.

X2 Very important. I'd try and get it on a lift, so I can get a good look.