I'm sanding on a 1940 Parkard coup I bought in December. Behind the B pillar, at the belt line, above the trunk and below rear window I encountered a silver colored material under paint and primer. Paint seem's original, black on red primer. The surface
shows crack's , like old filler. A magnet will stick to it. Could this be lead filler ?
I plan for now to just prime and paint over it. Replacing 1965 olds 400 with pontiac 400 and drive line. thanks