The gaskets on side lights have served 2 purposes , one for a water seal where it needs to be , the second to cushion the edge of the hard trim from cutting the paint causing a rust .
Back in the 80's the Buick Somerset would cut into paint and rust at the bumper extensions that went into the fender . They were made out off a hard plastic material so the had edges . Not all did but most and can still be seen today on them . We removed them , smoothed them over and after repaint reinstalled them with great success .
But there is no gasket for the 69 listed here, and that is what I needed. I just bought the new trim surrounds for the 69, and then the guy says...."Where are the gaskets to go with?" And I said, gaskets? Oooops....
OR just go to a hardware store an cut your own out of some weather stripping....about 10 minutes of work there. I picked up some LED bulbs for those but haven't tried them out yet - very interesting on how they made them!