Mark, congrats on a really cool find. I registered to this site to add my comments to this thread. I am not a treasure hunter, but I do study genealogy and history, so maybe I have a different perspective than some here. I do have ancestors that fought in the civil war and I have some treasured artifacts, but nothing as cool as your ring. I would love to have that ring from one of my gggg grandfathers. But I would in no way feel entitled to such a find. I would first be thankful that someone made such a find. I would be thankful to have a photo of it. And I would be thankful to have a chance to buy it at full fair market price if the finder ever chose to sell it, and I would not be looking for a family discount. I'd probably pay more than market because it would mean more to me. And in that case, you wouldn't be worried that someone was just wanting ownership of an item to cash the item.
This is different, imho, than an item where there is an existing widow or child. Too many generations to have some one guilt you on keeping your find. Well that's my 2 cents. I wish it was my gggg grandfather's ring. I'd be making you an offer! Maybe I'd have to outbid a cousin. And if you wouldn't sell, I'd respect that, and ask for dibs if you ever changed your mind.