I have a '69 Super Bee I am restoring and while stripping the body of old paint and body work I discovered that the factory lead seam sealer on the sail panels had been removed and filled with bondo.  There was slight surface rust underneath where the filler was.  I have never worked with lead before so I am wondering if I start with clean metal would I be able to fill the seam with perhaps some fiberglass filler with bondo over the top of that?  Any help would be appreciated.  Thanks!