Dunhill coding is notoriously elusive (John C. Loring spent the best of twenty years putting it together), but #4103 describes bowl size, finish, mouthpiece. I'm not expert enough to date by blast, but there should be a date code somewhere, consisting of two digits. On most Dunhills, it is stamped on the shank. Your pipe has hardly any briar in the shank, the rest of the stamps have lost quite a bit of depth and sharpness, so it could be elsewhere or it could be barely legible, but it should be there. I know assumptions have a well-deserved reputation, but by the looks of it I'd say this pipe has seen more than a single decade of use. The mouthpiece looks remarkably fresh, by the way.