Lincolnshire Rifle Volunteers officers tunic button c.1859 to 1881

A good original 1859 to 1881 period 'Lincolnshire Rifle Volunteers blackened brass large tunic button'; embossed Victorian crowned bugle within title surround; the reverse impressed with maker's details 'ALSOP DOWNES & SPILSBURY LONDON'. Very good condition, complete with original shank.Diameter approx 23mm.