12/21/19 at 11:11purchased this Niello box in Edinburgh this week and am really struggling to work out the two marks. At present I’m leaning towards a French maker, and a Minerva head for the 800 purity (the one with the crested helmet) but i can’t be sure. The diamond makers mark appears to me to show a crown surmounted by two circles missing a wedge. The initials GT look to flank the crown, and I can’t quite make out the number at the base of the diamond. Any thoughts, as I would love to solve this wee conundrum.