Very similar to the Capt Warren elsewhere in this site. Stamping on one side is DUNHILL, plus white spot on vulcanite mouthpiece. This side has INNER TUBE and 28 plus unreadable patent number.This seems to indicate 1928 if the usual coding is followed. That said I have found no trace of any Dunhill pipes other than briars. Check out with the Wally Frank Underslung on this site, that one has a meerschaum bowl
Must be the Dunhill provenance as it reached £161 dollars in 1st 20 hours on ebay. Hopefully the seller or buyer will supply images of the inner parts of this one to compater with Capt Warren.