Dug this flatty tonight, it says on the back "Best Plated London"..no biggy, but what's catching my eye is the Fluer De Lis with a wreath crescent on the back, I have dug many flatties, this is a first for me..it's the same size as a quarter
It would with the right knowledge, but as this was produced in the Golden Age of Buttons, there is no comprehensive book. You have most of what you need, its London Manufactured & circa 1820-30.