Dunhill's "DR" stampings

The "DR" (Dead Root) stamping on the left side of a Dunhill pipe corresponds to a straight grain.
"Dead Root" is a commercial label and doesn't mean the root was extracted when the tree was already dead.

Prior to 1932: All the DR's are Bruyere's.

From 1932 to the 1950s: The Root Briar DR pipes were stamped DR R.

From 1949 on: The DR are graded with letters (ascending): "A" to "J".
Examples:

The first stars appeared midth 1970's and were a brief attempt to grade the pipe both as to grain (the letter) and to size (the stars).
Example:

1979: the DR are graded with 1 to 6 (or 7?) stars.
Examples:

Stars grading may coexist on the same pipe with letter grading.
Example:

Stars and letter grading equivalency after 1979:

2000: Pipes with the Amber Flame finish are stamped with DR followed by flames playing the same role than the stars.

(Unknown max number of flames)