Another thing that older casters need to push is what I call "networking". Thats getting others to look for lead for you. Friends, Family members, co-workers, ect.
Sunday afternoon a buddy dropped off a nearly full 5 gallon bucket of wheelweights. They were stored in a barn for years and were extremely dusty. They were also 100% lead weights. No steal, no Zinc, and only a few valve stems. This was from a contact that I made long ago. He also says there are more and he will bring them to town the next time he is out there. "Networking" may not produce instant results but it works.