A very nice looking coin. It should be 0.925 silver. As you are no doubt aware there are lots of fakes of these around. I can't see anything obviously wrong with yours. Even knowing the silver content is unlikely to confirm whether it is right or not as the best fakes are made in good silver just like the originals.
How did you come by the coin? That is often the biggest clue as to authenticity. If bought from a reputable auction house with a qualified coin expert, you should be OK. If bought online or from a general auction house, I would be cautious.
Getting it in hand to a genuine expert, whether at an auction house or a grading company, is probably the only way to be sure.