You may need to try a tin piston liner instead. Maybe the base of biscuit tin or one if those steel coffee containers .
Could the end of the cocking leaver do with a Polish too.

Yes often PTFE can get damaged.I'd try tin sheet n a leaver end polish.

In all honestly I have a meteor never shot it or worked upon it.
But have many super sports, scorpions, air spotters lightning's.
Not dissimilar.

Persistence