couple of things; don't know how wide spread this is yet but here in CA they are getting away from lead in the wheel weights, can't remember what they are substituting but it might be something you want to remember and check on before you just throw a batch in the melting pot. 2nd, check around at plumbing supply places or call a long time plumber. Its being phased out too with building codes etc. but sometimes they will still want to repair an old cast iron septic line, or some such, using melted lead to seal the joints. (I gathered as many wheel weights as I could find but had to buy another 50-60 pounds to cast diving weights that we used back when we were gold dredging and a plumbing supply was the cheapest back then).
live and let live