This Silver-Plated Helmet Mount from the British Royal Military Exhibition is circa 1890. I have not seen another of these, and was fascinated by it. My clients always like eclectic, and this fits that category.
Size: 5 inches high by 7 1/4 inches wide (12.7 x 18.4 cm)
Condition: Some rubbing to plating, wingnut may be of later vintage, possible repair to banner. Wear commensurate with age and use.