The material used for the discs was NOT Bakelite, more a fibre material, known to many as 'composition'. 'Pressed Fibre' describes it quite accurately. As a matter of interest, below is an extract from a book 'After Battle' referred to on a Guardian blog, which describes the retrieval of bodies from the battlefield in World War 1:

"Reasons of morale,hygiene and humanity imposed this unpleasant fatigue. Men would have on the nose and mouth pieces of their gas masks and probably sand bags on their hands. Breast pockets would be cut to extract pay books. The red identity disc would be sent to the orderly room, the green one left on the body for identification.

Regards to all,