The rule to operate by is: The price is right if it is FREE! By all means, go back and take them up on the offer.
If you turn down the freebies, it may not be offered again.
You can always salvage the lead for trade goods.
BPCR bulets requires relatively soft alloy. Wheel weights may work, but they are usually too hard unless mixed with pure lead. Scrap bullets may be too hard too, or they may be usuable. .22 LR slugs for example, are almost pure lead. Lead hardened with antimony is usually used in jacketed pistol slugs.
By melting scrap, letting it set undisturbed, and then skimming off the tin-containing dross (impurities), you can get closer and closer to that soft lead alloy you want. Once you build up your lead ingot collection, you have the basis for trading for stuff you want and need.