Hard to say without a picture or brand name, and I'm no expert but the brass, the chimney, and the shade make me think either 40's or 30's. Find a brand and model number and that will tell you more. Aladdin puts the marks on the knob that cranks the wick up and down. Others do writing on the bottom or on the burner itself right where the chimney slips in.
More value for a complete set. You need a wick, flame spreader, and mantle to get the best value.
