Royal Navy HMS Topaze 1915 Hm silver torpedo pin badge

A scarce original First World War period 'H.M.S. Topaze pin brooch', in the form of a hollow silver torpedo with cut out applied title scroll, the reverse impressed with Chester silver hallmarks for 1915 and maker's details 'F.H.M' ((Frank H Mannox Birmingham.). Very good mint condition, complete with original pin fitting.Length approx 57mm.