Household Cavalry, Life Guards 1871 pattern Trooper’s Helmet.
A good example, with white metal skull, plume holder and red horsehair plume, with bi-metal Star of the Order of the Garter helmet plate with the motto ‘Honi Soit Qui Maly Pense’, surmounted E.II.R. crown, ornate backplate and oak leaf spray and ornate backstrap, brass rosettes and chin scales, brown leather lining, remains of original printed trade label, several dents, mostly minor, generally good condition £300-£400

The Helmet is possibly a Blues and Royals helmet, not a Life Guards helmet.