Totally clueless on this one 68 Newport bench seats was there ever a rubber gaskets on the mounting bolts for the front seats, if not I won't worry about it
Nothing on ‘68 Polara. Seat studs through the carpet, and the washer nuts on the bottom. I contemplated installing a masticated washer underneath the washer nut but but didn’t do it.
Most were probably undercoated, so were sealed anyway.