Rocketman is correct in so far as Joseph Manton is concerned. However should your gun bear the name, Manton and Co; it is legitimate because this business was aquired as a going concern in 1846 by the Wallis family .The Wallis family conducted operations in both Calcutta and in London [from 116 Jermyn Street, London]. Records show that the London business continued into the early years of the 20th;century.As a matter of interest, Burrard, in his book, "The Modern Shotgun,Vol;1" plate 5, page 38, uses an illustration of a Manton & Co; sidelock ejector to name the different parts of the gun. I have always thought that Burrard,s choice of the Manton was to avoid upsetting the London trade of the day.