Unfortunately the nomenclature is very smoothed out; I can just make out "MADE..... and the D in England followed by an underlined 8. The patent number is mostly gone but PAT and 34 is just legible under strong light. There is also the number "24" stamped after the 34 in the Patent number. The DR R B (the B is slightly larger) is strong but you can only just make out Dunhill, London. There is a small square stamp next to the D in Dunhill.
It seems that this pipe is stamped with a "B" as a grade and simultaneously with an "R" holding for a Root Briar finish. The DR letter grading was initiated in 1949, so I am unsure why there is a underlined 8, denoting 1948. Could this be one of the very first pipes to get a letter grade stamp just prior to 1949?
The square stamp was probably to help the retailer to take a decision about the price.
The overall condition is very good. No rim darkening, Bottom of the chamber is clean with a bit of bare wood showing. Stem is excellent with no tooth marks. Very large chambered pipe.