Currently, we can test a filter (new or existing) on a recent change (Special:AbuseFilter/examine/12345) or a logged action (Special:AbuseFilter/examine/log/12345). However, recent changes usually last only for a month.
It would be nice if we could test a filter on an existing revision, like Special:AbuseFilter/examine/rev/12345. Possibly, on a deleted revision as well.