Patent No. 417574/34 with underlined 3 denoting 1943. Also stamped 44 after the underlined 3. Shape number 335, "A" for Bruyere, and a group 2 in size.
While I've certainly seen Canadians from Dunhill before (see US patent listing), it's not a shape they're particularly known for and neither are they seen in a Group 2 size, making this piece somewhat of an anomaly.
All the stamping is crisp. The pipe is in very good shape, including the chamber which still shows bare wood. The inside of the rim shows the tiniest amount of knocks. The mouthpiece has a tooth indentation on the bottom half.