Most of the ones I have seen appear to have been plated/chromed after manufacture/issue , this suggests it was done by the factory or individual worker. While they may have been for supervisors , what would happen if someone was promoted/demoted ?
Officially these badges were meant to be returned when their contract finished , but obviously most were not , so perhaps a worker had their badge chromed/plated when they finished work as a keepsake (bling existed even then !) .
I have found no official documentation explaining thses badges , unlike the enamelled War Munitions Volunteeer and the first issue of the 1915 OWS badges.
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