Victorian Style 14k Gold locket/ pictures inside

I have recently came across this beautiful Victorian era Locket with pictures in it and initials engraved in the back or front, So I decided to do a blog or questioner on my facebook antiques and collectables page. I was getting overload of loves, Likes, and comments. Well one particular guy said that he had been appraising jewelry and antique items for 45+ years. So he inboxed me and said do you know what you have here? I said no all I know is I got a very beautiful gold locket, with pictures of people in it idk, and initials on it I don’t know what they stand for. He then responds and says let me help you a little. The Locket to me seems to be Gold of course, the Intials on the front/back are S and W that are intertwined, So the pictures I am looking at I would say to be very very rare along with the whole locket itself. He said the pictures are of “Billy the Kid” and his fiancé before he got shot and killed, her name was Sylvia, He said that the W and S are there initials. The S Of Course being for Sylvia and when you rotate the locket a half turn you see the W in which that would be for William H Mooney”aka” BILLY THE KID!! He then says congratulations on your find and told me to sell it nowhere else then Heritage Auction. So I am looking for more opinions and help! What’s all your guys thoughts! Please and thank you!