exposed hammer double

Just received an old damascus double bbl. 12ga. from my father. This is the first shotgun I used 38 years ago.It was my grandfathers, now it is mine. I am not to concerned about value ( I will never part with it) but would like to learn more about it. On top of bbl. is Belgium Royal Damascus, on the side plate under the hammer is T.Barher. This is all the markings I can find. Any information would be greatly appreciated.