The gold standard for gaskets back in the dark ages used to be rubberized wool felt. These days, the makers of "Fel-Pro" gaskets can trace their ancestry to "Felt Products Company" from the 1930's, I believe.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!