Hello, I'm going to restore a pair of original 6-pin wine glass GT40 Halibrand magnesium rims to factory finish, readying them for sale. I understand that the rims were originally treated with 'Dow 7' which gave them their characteristic colour. Does anybody have any advise or feedback about the restoration of these rims, the use of/application of Dow 7, or recommended service providers in England? Many thanks, Jamie