I know of nothing that can raise a date on the SLQ. There is Nic-a-date(Ferric Chloride) that people use on dateless Buffalo nickels but it only works with the Copper-Nickel coins. It does not work on silver-copper coins.
People have tried it, all it does is leave a black stain on the quarter.
People have tried it, all it does is leave a black stain on the quarter.


















