I recently found a leak in the interior of my 69 Elcamino, and it seems it's coming from behind the black plastic side moldings in the cab. I've tried to take this off, but it won't budge. I've removed the two screws holding it in place, but it seems there is an attachment located behind the plastic seat belt clip that I can't get to. Does anyone know how to take this thing off? Thanks for your help.

If you take a small flat head screw driver, there should be a access door to get two phillips head screws out that holds the plastic male clip that holds the female shoulder belt to the interior panel.