These pistols are probably one of the last products of Durs Egg's business, made between the death of the Duke of York in 1827 and his own death in 1831. His youngest son John used the same trade label from 1840, but changed the figure '1' on the Pall Mall address to a '4' in ink. The label in the case of these pistols appears unaltered.
For an account of Durs Egg's latter years see Claude Blair, 'The Egg Family, Part I (contd.)', J.A.A.S., vol. VII, No. 11/12, pp. 305-353. An example of an altered trade label used by John Egg is illustrated as plate LXXXIII A