THE HISTORICAL drama "Custer," in its umpteenth revival and revision at the Round House Theater, seems as long as history itself. It's unclear why Round House chose to open its seventh season with this tedious play, but with some generous trimming, school groups might benefit from it.

Director David Cromwell takes credit for adapting Robert Ingham's play, but his vision inflicts some fatal logical flaws on an already mixed-up work. In Ingham's original, the ghosts of Custer and company meet on a barren plain to rehash the Battle of Little Big Horn. Cromwell, in the name of immediacy, has banished the ghosts and moved the action to an 1896 tent show on the Chautauqua song- and-lecture circuit. The drama now hangs on the real-life figure of Mrs. Elizabeth Bacon ("Libbie") Custer, who actually did tour the country in such shows, attempting to make her late husband into a national hero.

Some of the figures at the Chautauqua -- Libbie Custer, the massacre survivor Col. F.W. Benteen -- are meant to be the actual historical personages; others are actors recreating Custer and his slain soldiers. Cromwell fails to keep this division clear. The re- enacted Custer argues heatedly with the accusing Benteen, reacting as if he were actually the slain general. And although this is ostensibly a traveling tent show, everyone acts as if this was the first time they had heard the story.

Cromwell's restaging is a disaster, burdened with cute directorial touches -- the audience stands for the Pledge of Allegiance, actors wander through the audience and deliver personal asides at intermission.

The flamboyant, foppish Custer's rapid rise and tragic fall is fascinating subject material: Did Custer and his men kill themselves when they found themselves surrounded? Was the Little Big Horn "campaign" scheduled to provide election-year publicity? But Ingham takes forever to get to the meat of the matter, and the play is further slowed with personal minutiae, Indian jokes and intrusive songs (music director Roy Barber's a cappella arrangements are quite artful, however).

The deliberately amateurish acting quickly becomes cloying. But Dion Anderson is strong as the robust and bitter Benteen. And as the Don Knotts-like Lt. Collins, Mark Jaster is genuinely funny, as always. His sometimes distracting mugging is welcome relief here.

"Custer" seems much more fun to be in than to watch. And why not? The actors are being paid for this. When not actually acting, they feel free to yawn, crack their knuckles and study the audience -- which is also yawning and squirming. CUSTER -- At the Round House Theater through November 4.