Silver plating solution is fine silver. However, it's not any less
prone to tarnish. It's not the copper in sterling, or the alloy in
particular, that tarnishes, it's the silver. A bit of trivia I've
always found fascinating, too: Silver didn't tarnish like it does
until the industrial revolution. All the factories and things from
then on have put so much sulfur in the air, from coal, that silver
tarnishes quickly. Back in Paul Revere's time they's polish silver
once a year for XMas.