Regarding The OP, they stopped using lead to solder cans because of the obvious health risks, don't know when, or how to ID old lead from moderns, Interesting topic I had never considered.
I came home the day after picking up the items to find my wife polishing them, (I prefer the patina)
That's when I examined the piece she was working on and discovered it was sterling.
Immediate photos for researching the item followed, hence the 'Banana Pic'.
I first reveled in the windfall then realized I had to knock. It came from a very small town where I used to live.
Shortly after I did the right thing, I recovered two 17th C silver coins from one hole in this town.
Perhaps it was just chance.