[KsGman]

Thanks Neil.
On our other bikes, the copper washer always sealed between the bottom of the case and the plug (ie-it comes off when removing the plug). It was different that this one is pressed up into the case, so I wasn't sure if the washer/gasket that came with the Matto replacement plug was supposed to be used in addition to the copper one.

Good idea though-I do need to check, if the diameter of the flange of the new plug seats properly on the existing copper washer, hard to see a need for the steel one provided.