WW2 Staffordshire Police Reserve numbered badge

A good original Second World War period 'Staffordshire Police Reserve lapel badge', chromium plated enamel example, the central disc depicting a 'Stafford Knot' and 'PR' on blue enamel ground, the reverse impressed with maker's details 'J.R.Gaunt London' and official issue number '480'. Very good condition, complete with original buttonhole fitting, no damage to the enamel. Height 29mm.