Use the sediment bowl as a template and cut a new one from any suitable piece of gasket material with an X-Acto knife. Originals were probably made from rubberized cork, but any kind of gasoline resistant gasket material should work.
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!