No felt, o-ring, or gasket for 216/235/261 distributors.
That fiber plug at the shaft end of the spring in the grease cup, does not serve the purpose of a seal - people have speculated on the purpose(s) that piece of fiber serves: perhaps in spreading the grease on the shaft, and/or giving a soft end to the spring, and/or that might serve to hold the screw-in grease-cup cap from loosening?.
