I read on another post named "damascus explained" on page 52 that Purdey made all it's own damascus barrels until about 1870 when the transition started to steel tubes. The previous post said this info came from Donald Dallas's book on Purdey history! A good description of the actual stamp is also provided. I recently purchased a thumbbreak Purdey with damascus barreles made in 1869. I've looked over the barrels carefully and cannot locate the stamp mark anywhere. Can anyone tell me where on the barrels this stamp mark would be located. Must be a secret place! Both barrels have the serial number on the bottom near the breech!