If I remember correctly, Dave, one of the back legs was pulled partially loose from the rail and the front end of the upper part of the bracket which bolts to the seat was cracked. The crack ran down the the center of the aluminum rail thru the mounting bolt hole and then emerged on the other side of the hole and angled toward the side of the rail. It was hanging by a thread.
Looked like the car had run into something and the seat had tried to lift from the rear...on the other hand, who knows?
Any way, that upper aluminium rail is awfully thin and does not inspire me with a lot of confidence toward GM engineering. I have a friend that is a great tig welder and he put it back together. I did put a large washer under the mounting bolt head to spread the load distribution out a bit. I was glad that William had one in his parts stash!