Where is the lead?

I just got a fax from Mopar34 the other day about chopping a Model A (thanks again) and it mentions something about not being able to weld the factory lead. I didn't realize there was any, anybody know where they're talking about I don't want to be burning that stuff with my welder. I was already starting to wonder if that was asbestos around the firewall at the mating surfaces. (put my mask on just in case).

Anything else I should know about:eek: .

Sean

There's probably lead filler in the seams.