Macdee washers for the float valve are available for the grey and white valve (blue and white is obsolete) but come with an outlet seal which I eventually worked out is the flush valve seal! They are a ridiculous price and I told them I'll just replace their valve with a Fluidmaster Pro! I suggest everyone do the same and forget about using or replacing a Macdee (Wirquin) valve that has very poor spares support!
IM Plumbing - St Neots
February 2012