Hi Steve!
I'm still forming my Junior study group to pin down the dates on these rascals, but the overall analysis remains without much date attachment yet.
What I can tell you is that the Junior predates 1912. I have one of the first Juniors with the wicket globe wires and outside lift that I would date at no-later than 1908. The Inside Flag lift plate, on the one depicted here, was used by Dietz on No.2 cold blast lanterns from 1909 until late 1919, and on the Junior until the mid 1930's. Later versions had Junior Side Lamp embossed on the reflector instead of Junior Wagon. The spiral wire burner indicates it is post 1920. There were at least 3 different bail designs and two different bi-lingual fonts enbossed in English and Hindi. Don't believe what you might read about the Hindi marked lanterns being some sort of over-production that never made it to India. This side lamp was made for sale in America. Side lamps made for India are a right-side mount, because they drive on the left.