Hi Joe, I don't have a '57 Chrysler but similar parts on my '60 New Yorker and '58 Plymouth are held by tinnerman nuts. They are just sheet metal nuts with a fast spiral self-cutting thread. They fit a 3/8 inch nut driver and you just unscrew them like regular nuts. Look closely at them before you accidentally twist one off though lest it be something else that I haven't seen. The diecast trim parts ( "Potmetal" seems so crude for a Chrysler product! Like the clowns who used to call 300 letter cars "brutes" -- ugh!! ;o) just have a diecast stud on them that the tinnerman nut screws on to. Since you say that this is only reached through a hole in the interior panel, I would assume that it was the same thing though. ) Kurt Kurt Greske ( kurt_greske@xxxx )