Lost art of using Lead and not bondo

lol, yeah you certainly don't hear that. And I don't think that using it as the only method of filler is a great idea. It takes longer, it's way more expensive, and then of course there's the toxic factor. So I still use filler for most of the work, I wouldn't use lead to fill a dent in a fender for example. But certain areas, like the roof/quarter seam, tail panel/quarter seam, rocker/quarter seam etc are a great place for it. It won't absorb moisture like bondo can, and it won't crack in those areas that flex. So if you're doing quarter panel replacements it would be a great skill to have to do the seams like the factory did.