Ouch,
Ever tried using the plastic thrust washer with the fiber washer fitted? I guess the only way this could improve things is if the fiber washer didn't rotate to protect the plastic but there is no way of guaranteeing this.
Sorry, off topic but I just thought of it, can anyone help me with a supplier for the red home plugs that fit in the chain case and height adjuster knob? Someone must make something close to the original!