Lead is a kind of sweetspot - easily available, it is a metal at room temperature and has low melting temperature. Probably tin (less available) and aluminum (higher temperature) would be the close contenders.
Japanese Repairman #9 (from a wonderful series) shows a man restoring one of his own vegetable (Daikon?) graters: he resurfaces the copper with a molten metal, any idea which? https://m.youtube.com/watch?v=mzOeKoYW6EQ
While a little pricey, Bismuth is relatively safe and can be melted stove top.
Of course you can still by lead melting pots at some bait stores along with molds for heavy sinkers.
I wish I still had the molds I was given when I was a kid to make lead soldiers.
