Being a 242 frame would explain why it looks like it's installed backwards. That design has a lot more forging vs. stamping, and subsequently burns a lot more efficiently.
I think the 242 lanterns got maximum fuel economy at something like 14-16hrs of continuous runtime compared to a mix and match of other lanterns. The heavy forged castings absorb a lot of heat from the mantle, vaporizing the fuel completely for a very clean burn, combined with only having one mantle and a very small needle valve orifice.
With the big fount that's on it, it could likely burn for 20-24hrs...
I think the 242 lanterns got maximum fuel economy at something like 14-16hrs of continuous runtime compared to a mix and match of other lanterns. The heavy forged castings absorb a lot of heat from the mantle, vaporizing the fuel completely for a very clean burn, combined with only having one mantle and a very small needle valve orifice.
With the big fount that's on it, it could likely burn for 20-24hrs...