Durs Egg Flint Lock

I have aquired a Durs Egg 50 caliber flint lock pocket or muff pistol. It has a 2 3/4 inch screw off cannon barrell. It has a fold up hide a way trigger and a safety. The pistol grip is a one piece checkered wood with what looks to be silver inlay on the backstrap, sides and bottom of grip. The bottom of the grip is in the shape of an egg. It has engraving on both sides. Left side says London and the right side says DE GG. There is no bluing on the gun. All parts on the gun appear to be in good mechanical condition and it still looks all original with no replaced parts. I have never seen a picture of the gun, but the gun itself seems to be in very good shape. I can use any help at all in identifying the gun and getting an approximate value that anyone might have...here are a few photos..thanks in advance for your help

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