Hi Ian, this is a matter of long experience. I have been specializing in old Russian coins for nearly 5ü years. There are many features. Take for one the letters indicating value and date. I do not succeed inserting links here, don't know why. Do copy it in your browser. It shows pictures of genuine coins auctioned in Russia. Compare and get an idea. Sleeping time for little boys here - Good Night
https://www.m-dv.ru/monety-rossii-1700-1917/kid,14/mid,18/nid,36/types.html