I have this coin that belonged to my father, which he purchased from an estate sale about 25 years ago. It wasn't actually sold separately, but rather it was auctioned off in a lot with a variety of other coins. I recognize the rarity of this coin and the potential for it being fake, but I would really appreciate input from anyone who could lead me in the direction of determining whether or not this coin is authentic or not. The coin has been weighed at 26.3 grams.

I am posting some pictures here in the hopes that maybe someone on this forum will know a bit more about this coin than I do.

Thanks in advance.