I seem to remember some of those filters using a soft copper washer between the top bolt and the canister lid. Most good-quality parts stores like NAPA will have a copper washer assortment for oil drain plug gaskets, and you'll probably be able to find a good match if you're having leakage problems at the top bolt.
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!