THE SHADOW OF A GUNMANTragedy by Sean O'Casey. Directed by Shivaun O'Casey. At Symphony Space through Dec. 8. 'AND what danger can there be in being the shadow of a gunman?" asks Donal Davoren in the rhetorical question that provides the title for Sean O'Casey's 1923 tragedy. Danger aplenty as it turns out. But not for Davoren, the would-be poet, nor for the blowhard Seumas Shields (Niall Buggy), from whom he rents sleeping space in the rundown tenement whose residents all suspect that Davoren (Ian Fitzgibbon) is an IRA gunman in hiding. Davoren assumes the imposture with a kind of cavalierness that breaks down only when he belatedly confronts the consequences of his behavior. The terror that lurks outside touches these Dubliners directly and indirectly. In his first play to be staged, O'Casey mingles intimations of impending disaster with characteristically comic sketches. Chief among them is the egoistical Seumas. A smalltime peddler, he complains constantly, blames everyone else for his problems, oversleeps regularly, and has an extraordinary talent for becoming entangled in his bedclothes. The O'Casey casuals come and go, adding to the local color and, in some cases, advancing the ominous plot. Among the early arrivals is pretty Minnie Powell (Michelle Fairley), who pays a neighborly visit to borrow some milk and becomes innocently involved in the chain of events that leads to her betrayal. The Dubliners of the entourage include garrulous Tommy Owens (Risteard Cooper), bibulous Mr. Grigson (Sean McCarthy), his longsuffering wife (Pauline Flanagan), expansive Mrs. Henderson (Doreen Keogh), and timorous Mr. Gallagher (George Vogel) - not forgetting Mr. Maguire (Richard Holmes), Seumas's fellow peddler, who leaves a bag containing more than peddler's wares. Under the direction of Shivaun O'Casey, the playwright's daughter, the members of the O'Casey Theater Company respond to the robustly comic, as well as to the melodramatic, philosophical, and mordantly ironic qualities of the text. Davoren expresses a typical theme: "There is an ugliness that can be made beautiful, and there is an ugliness that can only be destroyed, and this is part of that ugliness." Minnie's final act doesn't redeem the ugliness but it is at least a recklessly gallant gesture. It is l eft for Davoren to indict himself and Seumas, the "notable cowards" who have betrayed her. Mr. Fitzgibbon's delivery of the self-accusation caps a telling portrayal. The production's solid values extend from the acting to the visual and atmospheric details of the Irish-American collaboration. These include Brien Vahey's set design, Josie MacAvin's set decoration (together achieving the "absolute untidiness" prescribed by O'Casey), Rory Dempster's murky lighting, and Jan Bee Brown's period costumes. "The Shadow of a Gunman" will also play Philadelphia's Annenberg Center (Dec. 10-15), and the Kennedy Center in Washington, D.C. (Dec. 17-Jan. 19).