I am looking for some material to turn up a piston support washer for a Britannia. I have purchased washer kits from TW Chambers and John Knibbs over the years, they have a green plastic washer. It looks like a material I used to buy many years ago named 'Murfeldt', some form of nylon, Polypropolene, Acetal? any ideas? if so where could I obtain?

Ormicron