Eh Noodlearms? The figures provided in your second link are only true for an item made from 100% silver. I doubt that the OP's coin is made from pure silver due firstly to the cost and secondly, the softness of the pure metal.
Once you disregard pure silver, you have to consider that the coin is made of an alloy. There are thousands of silver alloys. Fractional alterations in densities of an alloy would put you off track so it's a waste of time. Furthermore, I doubt whether the OP could access a sufficiently accurate scale to do this work himself.