Run, don't walk away. There are too many good 5th wheels out there to buy one that has to be "made right". I would feel that if this portion of the 5th wheel has to be repaired, then it possible there are other parts that will need it but don't fail often enough to be recalled. I wouldn't touch it with a ten foot pole, or a five foot Slav. Har, har. Seriously, I would keep looking, there's lots of 5th wheels out there.
Howard and Peggy
"Don't Panic"