The Judas Pair (Lovejoy 1)

Every antique dealer is a bit of a detective, following clues to find the trophies that pay the rent, but when Lovejoy takes on the job of tracking down a pair of duelling pistols so rare that he's not even sure actually exist, he needs all the instincts of a detective to pick his way through an unsolved crime. Along the way, he becomes convinced that the weapons do exist but that they have fallen into the hands of a vile murderer. Locating the ancient weapons seems like the least of his problems when Lovejoy then finds himself fighting for his life in a duel to the death!