A French Napoleonic Imperial Guard Train of Artillery Helmet Plate 1806-10.
A scarce Model 1806-10 Helmet Plate, 175mm x 120mm, brass, probably from Waterloo, missing orb off crown and 1 loop fixing from rear, otherwise good condition £800-£1,000

See ‘Aigles et Shakos du Premier Empire’, by Christian Blondieau, undated, page 34, fig.79, for an identical example, also missing orb.