Specific gravity test is a possibility or some pawn shop or refiner that has an xrf analyzer. Silver acid test would tell but only on the surface. The xrf will be the same way. A refiner could also do a fire assay test.
The signs are obvious. They are the same fake Chinese coins my employees have seen dozens of. I have the sigma metal tester pro, the pfisch testing kit a magnetic slide none of which were used by my employee. The absolute sign was that the guy had a buffalo new york id. If you want to see one...
If anyone gets coins tested, make sure they have either of these testers. I have both. They both work.
Pawn Express in Newnan or Lagrange can test your coins for you. If you only want them tested just tell whoever helps you that you only want to know if they are real and as them to test them...