TERRORISTS also play a role in The Long Count , a Fawcett Gold Medal Original. Ordinarily, book pages give paperbacks a bye, and with good reason -- aside from a few westerns and a lot of science fiction, paperback originals belong to the scrubs, a circumstance that makes this little volume gleam like a pearl in a refuse bin. It isn't that the plot is original or ingenious; slightly altered to fit the circumstances, it is the same old reliable tale of the hard-bitten diamond in the rough who works its way out of a tight corner with only his code of honor to aid him. wA boxer named Racine finds himself stranded in a South American country, gets himself kidnapped (along with the U.S. ambassador and a pretty girl) by leftist guerrillas, and wins through to a bittersweet freedom in the end. Purity of motive is everything in stories like this, but what distinguishes The Long Count from its hackwork brethren is Ron Faust's taut prose, his splendid eye for detail and his ability to create a central character who is not only interesting but unusually intelligent. A slight book and somewhat hide-bound by its faithfulness to the conventions of the genre, but appealing nonetheless.