BRODERIE ANGLAISE by Violet Trefusis, introduction by Victoria Glendinning (Harcourt Brace Jovanovich: $13.95;). This is the first English translation of Violet Trefusis' third novel, which was published in French in 1935. It owes its unlikely resurrection to a continuing fascination for all things Bloomsbury. Violet Trefusis was the woman with whom Vita Sackville-West eloped before becoming involved with the novelist, Virginia Woolf. Trefusis grew up in luxury and in shadow, for she was the daughter of Alice Keppel, Edward VII's mistress. After an unhappy childhood and her elopement with Vita, she settled in France, married, and published six novels. In an introduction that gives us a good deal of biographical information, Victoria Glendinning, a biographer of Sackville-West, provides the key to the models for each character. She justifies the publication of this "literary curiosity" by explaining that Sackville-West's son Nigel Nicolson has told his mother's side of her romance with Violet in "Portrait of a Marriage," and Woolf her account in "Orlando." This is an explanation from the third side of the romantic, (and literary) triangle. The slight plot involves a famous English novelist, modeled on Virginia Woolf, and her infatuation with a suitor who claims to be holding a candle for an earlier love. In her novel "Orlando," Woolf portrays Violet as the "faithless, mutable, fickle" Russian princess. Here Trefusis depicts Woolf as a vapid, cerebral and passionless virgin.