Try asking some tire shops for there old wheel weights. You will have to do some sorting though. There are clip on that are fairly hard, stick on that I think are very close to being pure lead. You also have to sort out zinc, steel, and composite weights. This may be a bit more labor intensive. Depends on how many jigs you want to make, but, it is another avenue to explore. You could also check with roofing companies They sometimes have scrap that comes off of roofs.