Here's the way I see it. I didn't feel that anyone was questioning the validity of the find at all. When someone responded "same pic on facebook with no back story" they weren't trying to say you didnt find it, just that you didn't add any story or description to the pictures of the find. Its just that people like to hear the treasure hunting story to go with the post. You can use generic terms like farm field, colonial homesite, old creek bed etc. without giving up the location of the hunt site. Then you can add in things like detector used, what kind of signal the target was, depth, etc. Mkaes for a much better presentation of the overall product. And by the way, AWESOME FIND!

Hope there's more to be found there. Congrats!