If you use the search engine and search for headliner staples or maybe it was "headliner staples" you should find this lists of threads on the subjecting of replacing and installing a headliner. Including information about staples. Those used by Ford back then do not seem to be available any longer. Alexander said he used regular 3/16" staples for a staple gun. Look through the other threads listed also. They may be some help to you.