There's one true standout in this just-passable collection of 15 mystery/suspense stories from Britain--but it's hardly a fresh arrival: ""Great Aunt Allie's Flypapers,"" a fine mini-puzzle for P.D. James' Supt. Dalgliesh, appeared five years ago in two US-published anthologies (Verdict of Thirteen, Best Detective Stories of the Year 1980). Otherwise, a few reliable veterans here provide neat diversions. Peter Lovesey, master of Victorian-crime atmosphere, amusingly compresses a tale of sexual jealousy and murder, 1878-1885, into eight elliptical pages (excerpts from a newspaper's advice column). Michael Gilbert's ""The Killing of Michael Finnegan"" is an above-average, unusually active case for spymasters Calder and Behrens--who foil an IRA assassination scheme. There are sturdy variations on familiar plots--angelic child eliminates would-be stepfather, put-upon wife kills boring husband, cuckold takes revenge--by Antonia Fraser, Julian Symons, and Celia Dale (who deftly squeezes her whole story into a brief ""Business Lunch"" monologue). And Celia Fremlin's ""Bluebeard's Key"" presents an interesting situation: a dedicated, inept social-worker saddled with an incorrigible problem child. The other entries, however, don't even reach the level of uninspired competence. ""Inspector Ghote and the Noted British Author"" is much-below-par H.R.F. Keating--with a weak mystery and belabored drolleries. Christianna Brand offers an implausible psycho-sketch; Joan Aiken supplies limp gothic chills; stories by Clare Dawson, Penelope Wallace, Madelaine Duke, and Tony Wilmot are creakily contrived. And dimmest of all is ""Detective's Wife,"" a crude, corny mini-melodrama by editor Harris--who too often throws one of his own amateurish efforts into the annual Creasey anthology. Serviceable but skippable--especially for libraries which already have the P.D. James story on hand in one of those 1980 volumes.