A few items that would have made this thread a bit more informative. The fact that the edges were marked ".999 FINE SILVER" should have been stated earlier in the thread. Why? Many plated "collector" items are marked ".999" or "999" describing only the plating. Leaving out the words "FINE SILVER" when describing the edge left several members leaning in the direction of plated copies. Please describe your finds as accurately as possible to get an accurate evaluation earlier in the thread.
Related to this is the delay of images clearly showing the edge lettering. While it is not always possible to immediately have clear images showing all detail of your finds, they certainly help.
While providing accurate descriptions and images do not guaranty accurate identification by members, doing so certainly helps.
The other point that made a few members default to cheap fake had nothing to do with your description, but rather modern regulations requiring copies to be clearly marked as such. Seeing the word "copy" on the face of the coin before seeing the ".999 Fine Silver" on the edge, leans me toward the opinion of cheap plated junk.
These silver "Quarters" would have been far more appealing had the word "copy" been on the edge, and not on the face.
Your find here is very inspiring to look at. Could you give a bit more detail on how it was offered to you, and whether the asking price was a bargain. Also looking forward to your next find. This one looks to be a winner. Congrats.