The Chambers model BZ was made from very late 1947 through 1948. It’s the bridge between the model B and C. The BZ has the more efficient broiler that the C would eventually have, new burner grates, a new oven baffle, an improved heat shield on the door and the “wagon wheel” pilot cover in the center of the smooth stove top. The Thermowell and styling are the same as the B.