I can't disagree with anything you're all saying but my intention was to convince the seller, not ridicule him (which is why I din't name him). Maybe I wasn't that careful myself. Actually I thought of a belt buckle as well, even though it probably isn't one if it's really lead.
You've been very sensitive and gentle with the seller's feelings, however as he has not withdrawn the badge based on a soft approach, I think a little laughter might now
help.
I'm thinking more of a small badge like those little metal badges in a thousand varieties that are so popular at Olympics events, or perhaps a plaque to be affixed to something - luggage, a sports
trophy, a soldier's kit? Given it's made of lead that might, to give the seller credit, date it to before lead was considered dangerous. Perhaps the LA Olympics - not 1984 but 1932.