Coin silver was historically a source of known/guaranteed quality material for eating ware. Next higher quality was sterling silver but I have no idea how silversmiths acquired that.
A friend of mine used to electroplate some car parts like dashboard hardware with silver using older Australian silver coins. The coins minted before 1947 (approx) had a higher silver content. I don't remember what he used to dissolve the silver, but the coins were one electrode.
Ol Reverend Burbank's book called out how to make Gold chloride from USA Gold coins. That was decidedly pre-1933 confiscation of gold by Franklin Roosevelt. After all, with the Federal Reserve taking care of our gold instead of a $20 gold piece being worth 20 dollars today it's $1900! Now that's progress!
Not that, but I have by means of an experiment dissolved a tiny bit of silver wire (used for jewelry) in nitric acid. I then proceeded to make a salted paper print with the dissolved silver nitrate. It worked.
You don't want to do this in any significant quantities without knowing *exactly* what you're doing and with very good ventilation throughout the process.