WW2 Royal Marine Police special reserve badge

A scarce original wartime 'Royal Marine Police badge', die-cast nickel example, depicting the globe within a laurel wreath, with tablet below "R.M.P", the reverse with maker's details "Firmin London". Very good condition, retaining original buttonhole fitting.
Height 28mm.

Worn by both the main force and Special Reserve Police whose duties were to guard the dockyards and Royal Navy shipyards.