"Fenders Bouncing"?
On my 56 Wagon, I found the front x member weld broken, I think it was the R side and a Shop welded it for me. The X Member appeared to be in good condition and the Shop said it was a common? issue on these cars.
It also became apparent something was missing, a Bracket that supported the front sheet metal to the frame. Looking at the solo eyelit on the front side of the X Member is the bolt up area to the underneath of the center line of rock shield, hood lock area.
The radiator frame was bolted to the rearward eyelits with hard rubber grommets, no springs, those were replaced also.
I don't know if I'm seeing bouncing fenders or the result of our poorly maintained roads here in CA. Any other conditions relate to bouncing fenders?