WW1 On War Service 1915 munition workers enamel badge J.R.GAUNT LONDON

A scarce original First World War official issue 'On War Service 1915 munition workers badge', gilt brass Crowned blue enamel oval title, the centre bearing the 'Board of Ordnance' shield on white enamel ground, the reverse impressed with maker's details 'J.R.Gaunt & Son Ltd London' and official issue number '75293'. Very good condition, complete with original buttonhole fitting, no defects to the enamel. Height approx 43mm.