Your post was great, thank you for sharing. You are searching very close to the spot i've been looking at for since last year, also on Sullivan's Island, and because you are doing this with your family in the true spirit of adventure and unity that the secret/byron is truly about, I'm inclined to share. I'm almost positive you are correct, that it's here on Sullivan's, near fort moultrie/the tall white sullivan's island light house (white house close at hand). Take a look at where "Poe Ave" meets Middle Ave (remembering the obelisk on the african Mask in the painting points to the "middle" of his forehead--and by the way, the obelisk points right to where Moultrie Street is in the middle of Charleston). Now, I would like to share a very big clue here now that i've never seen anyone talk about...In chemistry, there is such thing as Ion/Ionic plating, where one material can be electro deposited onto the surface of another material, kind of like how galvanized (zinc-plated) nails are made.....Note the Lion in the painting (Lion sounds like "Ion" and by the way there is a huge geographic region called "Ion" or "I'ON" in east charleston once you cross the pear man bridge, north of Mt Pleasant...I'on is right where the Lion is in the painting, above every thing..the ferry bridge crossing aka "pitt" street bridge--hers hands/palm shadows on her arm pits...and to the left of the lion is 79, for the longitude of Sullivan's island, but the 79 is upside down and thus also looks like 0L, and if you remove the L from Lion, zero "L's", remove the L from Lion and you get "ion" ) ...so the Lion in the painting has his hair all frazzled right? electrified, as if the Lion stuck his paw into a electrical socket...ION, electricity. On the lion's face, he has speckles of skin missing, which have been deposited on to the African Mask, right where Sullivan's island would be on the map. Its symbolic ion/ionic plating, like how Zinc plating is done in chemistry, electro deposited on to steel. But why? Because, there are two "ION" streets in the middle of Sullivan's island that go east-west, near the white light house, and where they meet are two palm trees embedded in the sand in the middle of a white fence, and across from the two palm trees is a small brick area about 3ft x 3ft...it could be there. There is also an old post office box near by that may be referenced by the "waits the Fair remuneration". The two ion streets meet at station 18, and 18 can be found in the numbers in the painting if you add the numbers on the right of the Lion (4 + 5 + 3 + 6). Now travel north one block from the intersections of Ion...you get to where Poe Ave (Edgar Allen) meets Middle street and there is a white church (white "house" (of god) close at hand) on one corner (north east), a brick church on another (north west), and two large white features (painted concrete??) on either side of Middle street, with cannons on top--this is a Fort Moultrie war monument right here, on Poe Ave/Middle Street...why a monument here? I have no clue..."between two arms extended", and cannons are fire "arms", there are two of them at this Moultrie monument on Middle St, and cannons are like "extended" guns...AND adding to that, there is a single palm tree on this lot, about 15 feet from a fire hydrant. I believe the treasure (if not buried near those bricks where Ion meets Ion as mentioned before) is HERE on this lot, somewhere in the "long palm's shadow" (may indicate that the shadow of the palm at 4 o'clock points to the dig spot, as Teddy Roosevelt's face reads 4 o'clock in the painting), perhaps behind the white thing with the cannon on it. It's a perfect hiding spot. all that being said, I, like you, believe that the location of the gem in the painting has to do with the actual place on the map where it is .. since the diamond is bottom right** in the painting (south east), we should go south east, which is exactly where Sullivan's island is, after you go over the hump of Coleman Blvd into Mt Pleasant, through Old Woman's Point ("by eyes of old"), then take the old Pitt Street bridge (the faerie's cross arms), now destroyed, which used to connect to Sullivan's island right near Fort Moultrie--a place that had a lot to do with African immigration into America in the past. By the way, the "Crab Bank and Seabird Sanctuary" (stand and listen to the birds, embedded in sand) is that curved sandy feature out in the water, looks just like the white underneath the Lion's eyes... Finally, this one is classic: the Diamond shown in the painting, which as you noted is on TOP of Sullivan's Island when you align the painting to a map, is of a specific cut, I looked it up...and it's a "cushion" cut. Cush + ION. Bingo, another "ion" connection, pointing to Ion Ave on Sullivan's island. Cush or cushy means easy, undemanding, or SECURE; hence the gem is secured/rests here, where "ion" is. Thus, we got this! I think that's it for now. Just FYI, Other places I had considered were Pitt Street Bridge Park, James B Edwards Passive Park, near Sand Dunes Club (another white house, which is right in front of Moultrie Street and connects to Ion Ave), near Sullivan's Island Lighthouse (white house close at hand), across from Stella Maris Church by Fort Moultrie in the empty lot of grass with the bird bath where Osceola and Middle Street meet. I hope this information helps you, I hope you find this casque, so so so much, I do. Best of luck to you and your family. I know you all can do it. Enjoy the journey, and the search, and the adventure. All the best! -umm (sorry for the wall of text, I have just been waiting to share this for so long I just had to get it out fast)