round stone like

Hard to say anything for sure about the stone (s) without seeing them in person, the signature however might be a clue... I think it might be this guy: en.m.wikipedia.org/wiki/william_john_mcgee
They are probably reproductions, but I would have them evaluated in person by a professional appraiser, as even a reproduction can have significant value, especially if it belonged to or was made by an important historical figure...